Abstract: A hoist or skip conveyance for high speed hoisting operation within a vertical mine shaft is provided with sets of modules of guide rollers which engage sectional guide beams or girders extending the length of the shafts to steady the passage of the conveyance up and down the shaft. Each modular guide roller set for the system incorporates three guide rollers mounted for ready access on the outside of the respective guide module, to facilitate repair or replacement thereof. The load absorbing components for each guide roller comprise an air bag, permitting specific pre-loading of the roller, and an elastomeric high rate bumper spring to accommodate impact loads, while providing rebound capability and associated hysteresis damping, for smooth, chatter free operation of the system. The system may be specifically set up to counter the significant torquing effect of the hoisting cable.
Abstract: A process for producing a low alloy white cast iron is disclosed. The process comprises the steps of selecting one of a group of four alloying elements for a nickel, molybdenum/copper or modified low alloy iron; the four alloying groups consisting essentially, by weight percent of about:Group 1: 2.5 to 4.0% carbon; 0.3 to 0.8% silicon; 0.3 to 0.8% manganese; 0.75 to 2.0% nickel; 0 to 0.75% chromium.Group 2: 3.0 to 4.5% carbon; 0.3 to 0.8% silicon; 0.3 to 1.0% manganese; 0 to 0.8% molybdenum; and 0.3 to 1.0% copper.Group 3: 3.0 to 4.5% carbon; 0.3 to 0.8% silicon; 0.3 to 1.0% manganese; and 0.3 to 0.
Type:
Grant
Filed:
January 8, 1990
Date of Patent:
July 23, 1991
Assignee:
Norcast Corporation
Inventors:
Jean C. Farge, Michel Lefebvre, Robert Fortin
Abstract: A process for producing a low alloy white cast iron is disclosed. The process comprises the steps of selecting one of a group of four alloying elements for a nickel, molybdenum/copper or modified low alloy iron; the four alloying groups consisting essentially, by weight percent of about:Group 1: 2.5 to 4.0% carbon; 0.3 to 0.8% silicon; 0.3 to 0.8% manganese; 0.75 to 2.0% nickel; 0 to 0.75% chromium.Group 2: 3.0 to 4.5% carbon; 0.3 to 0.8% silicon; 0.3 to 1.0% manganese; 0 to 0.8% molybdenum; and 0.3 to 1.0% copper.Group 3: 3.0 to 4.5% carbon; 0.3 to 0.8% silicon; 0.3 to 1.0% manganese; and 0.3 to 0.
Type:
Grant
Filed:
July 15, 1988
Date of Patent:
March 27, 1990
Assignee:
Norcast Corporation
Inventors:
Jean C. Farge, Michel Lefebvre, Robert Fortin