Stock material or miscellaneous articles – All metal or with adjacent metals – Laterally noncoextensive components
Reexamination Certificate
1998-07-17
2001-01-09
Speer, Timothy M. (Department: 1775)
Stock material or miscellaneous articles
All metal or with adjacent metals
Laterally noncoextensive components
C428S627000, C428S681000, C428S685000, C164S095000, C164S097000, C164S108000, C241S275000, C241S195000, C241S197000
Reexamination Certificate
active
06171713
ABSTRACT:
TECHNICAL FIELD
The present invention relates generally to iron alloy members with improved wear resistance and a method of making the same, and more specifically to white iron alloy members of the type employed in centrifugal impact rock crushers.
BACKGROUND ART
Wear and abrasion resistant, high impact, iron alloy members are employed in a variety of applications, in particular, in rock crushing machines for crushing rocks and ore. A common machine used for crushing rocks is a centrifugal rock crusher, such as disclosed in U.S. Pat. No. 5,533,685.
Centrifugal rock crushing apparatus typically contain cast iron impact members called impeller shoes, which throw or propel rocks against stationary members called anvils to effect crushing of the rock. Both the impeller shoes and the anvils are subjected to repeated, high force impact loading, which of course is necessary to break apart the rocks. During operation of the rock crusher, the impact surfaces, or wear faces, of the impeller shoes receive tremendous abrasion and wear, which after even a few hours of use require replacement of the shoes. Consequently, the type of material used to fabricate the impeller shoes, as well as the anvils, is of critical importance.
Replacement of impeller shoes, as well as of anvils, requires complete shut down of the machine, in order to gain access to the impeller shoes. Shut down of the rock crusher can last for 2-4 hours, in order to remove and replace the old impellers and anvils. Consequently, rapidly wearing rock crusher components significantly increases downtime and maintenance, which adds cost to the operation. Thus, it is highly desirable to provide an iron alloy member capable of withstanding high impact yet also having increased wear resistance, particularly at the wear surface.
Cast white iron alloys are economical to produce and are widely used in the rock crushing industry. White iron alloys have been found to be one of the more impact and wear resistance of the iron alloys. However, impeller shoes made from these alloys still require frequent replacement due to significant wear and abrasion. Conventional cast white iron impellers and anvils can require replacement after as little as 6-8 hours of use. The useful life of rock crusher impellers can be longer, for example, as long as 40 hours, depending upon the material being crushed, but in every case, it would be desirable to increase the life of these critical rock crusher components. Despite there drawbacks, white iron alloy impellers and anvils are, however, still the preferred choice for use in centrifugal impact rock crushers.
DISCLOSURE OF INVENTION
Briefly described, the present invention comprises a wear-resistant, high-impact iron alloy member that includes a front side, positioned to impact rocks to be crushed, which includes at least one raised portion formed of a composite material including a white iron alloy and granular carbide. The provision of carbide material within raised portions of the front impact surface of the alloy member substantially improves wear resistance of the member. Preferably, the front side includes a plurality of raised portions, each formed of a composite material including a white iron alloy and granular carbide. The plurality of raised portions form a series of half column members that receive the brunt of impact forces from the rocks. The front side includes additional raised portions, one of which is an upper rim, another of which is a lower rim, and a third of which is a raised portion between the upper and lower rims, each of which is formed of a composite material including a white iron alloy and granular carbide. This design specifically provides reinforcement at critical points on the front side of the alloy member.
The present invention also includes a method of casting a wear-resistant, high-impact, iron alloy member having at least one wear surface, comprising the steps of creating an impression in a mold that is compatible with an iron alloy material, the impression being formed in an area of the mold corresponding to the wear surface of the iron alloy member to be formed by the mold, positioning a quantity of carbide granules in the impression prior to pouring molten white iron into the mold and pouring molten white iron alloy into the mold with the carbide granules in the impression, to cast the iron alloy member with a matrix of white iron alloy and the carbide granules formed in the impression area. Preferably the mold material is made from a sand material.
According to an aspect of the method, a series of impressions are created in the mold and carbide granules are positioned in each impression prior to pouring molten white iron into the mole. The impression is defined sufficiently to contain the carbide granules as molten white iron is poured into the mold.
These and other features, objects, and advantages of the present invention will become apparent from the following description of the best mode for carrying out the invention, when read in conjunction with the accompanying drawings, and the claims, which are all incorporated herein as part of the disclosure of the invention.
REFERENCES:
patent: 4119459 (1978-10-01), Ekemar et al.
patent: 4787564 (1988-11-01), Tucker
patent: 4796822 (1989-01-01), Terrenzio
patent: 5007475 (1991-04-01), Kennedy et al.
patent: 5183518 (1993-02-01), Radon
patent: 5190092 (1993-03-01), Ravankar
patent: 5439535 (1995-08-01), Snagovski et al.
patent: 5533685 (1996-07-01), Heck
patent: 5765624 (1998-06-01), Hathaway et al.
Smith Jerry I.
Stout Anthony E.
Flehr Hohbach Test Allbritton & Herbert
Smith & Stout Research and Development
Speer Timothy M.
Stein Stephen
LandOfFree
Iron alloy member and method does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Iron alloy member and method, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Iron alloy member and method will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2515659