US 4,589,502 AGranted

Earth boring apparatus

AssigneeCementation Company of America, Incorporated

InventorsMartin de G. Salter, John G. S. Hynd

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Abstract

An earth boring or shaft sinking apparatus in which a column is continuously rotatable about its axis, the column including a cutting wheel at one end rotatable about a wheel axis normal to the axis of the column, the cutting wheel including sprockets mounted about the wheel axis, the sprockets providing engagement for an endless bucket-carrying chain for direct conveyance of cuttings from the bottom of a hole to the top end of the column, which includes another set of sprockets for the endless bucket-carrying chain and discharges the cuttings into a feed bin. The cutting wheel is continuously rotated about the column longitudinal axis, as well as its wheel axis of rotation. In one example, a main, enlarged, cone-shaped cutting head is rotatable with the column for rotation about the column axis at a selected rate of speed, while the cutting wheel is additionally rotated about its wheel axis at a different selected speed, rotation of the cutting wheel and of the cutting head being continuous, the cutting wheel providing an advancing central bowl shaped recess adapted to serve as a lead or pilot hole to receive cuttings from the second enlarged main cutting head. Different arrangements of cutting wheels and endless bucket means are provided.

In an earth boring apparatus adapted to continuously excavate a pilot hole by rotation about two axes while simultaneously continuously excavating a main shaft, by rotation about one of said axes, the combination of:

an elongated frame means;
an elongated column means within said frame means and having a through passageway;
a main cutting head of conical form carried by the lower end of said column means;
first drive means on said frame for continuously rotating about a first axis said column means and said main cutter head at a selected speed;
an endless bucket means extending along said column passageway and having a lower portion extending below said main cutter head;
spaced sprocket means for the lower portion of said endless bucket means and having a hub rotatable about a second axis normal to the first axis and below said main cutting head;
a cutter wheel on said hub between said spaced sprocket means and rotatable with said sprocket means about said second axis and with said column and main head about said first axis;
said cutter wheel having spaced cutter elements projecting therefrom;
said bucket means having buckets spaced a selected distance apart to receive therebetween a cutter element as said cutter wheel rotates and said endless bucket means travels around said sprocket means;
a second drive means for continuously rotating said cutter wheel and said sprocket means about said second axis while said main cutter head and said cutter wheel is continuously rotated by said first drive means about said first axis;
the extension of said column lower portion below said cutter head and the continuous rotation of said cutter wheel and sprocket means about both axes continuously excavating a pilot hole and disposing of cuttings from said cutter wheel by said bucket means for reception of additional cuttings from said main cutter head and the direct removal of all of said cuttings from said pilot hole directly to the opposite end of said endless bucket means.

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Abstract

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