US 4,059,309 AGranted

Apparatus and method for cutting elongated slots in earth formations

OwnerJames M. Clearyinventor

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Abstract

An apparatus for cutting a deep slot, having a large depth to thickness ratio, in earth formations, which includes two main components, a motive means and a cutting assembly; the motive means, such as a crawler tractor, supports the projecting end of the cutting assembly, supplies a small portion of the driving force needed to advance the cutting assembly, and provides, through various connections, power, control functions, and the fluids required for operation of the cutting assembly; and the cutting assembly, extending the full depth of the slot along its advancing edge, includes an elongated support, a reciprocating cutter bar mounted on the leading edge of the support, a passage incorporated in the support for transmitting a fluid, generally a high gel strength clay paste, along the support and discharging the fluid in the interior of the slot, in a sufficient amount and under sufficient pressure to resist the earth pressure tending to close the slot and to provide a major portion of the force necessary to move the cutting assembly forward against the advance edge of the slot.

Claims11

Dependent claims

Apparatus for cutting in earth formations a deep slot having a large depth to thickness ratio comprising;

a long support means disposed adjacent the advancing edge of the slot and extending from outside the slot to its full depth;
cutting means guided on the forward side of said support;
a passage extending the full length of the support adapted to discharge a fluid into said forward clearance to flush material from the slot;
a second passage extending from outside the slot along the support to an intermediate depth for discharging paste mixture into the excavated region at the rear under pressure which acts on the sides of the slot preventing the slot from closing on the support and which acts on the rearward facing area of thes support providing the force required to move the support forward against the advancing edge of the slot;
projections on the forward portion of said support making close contact with both sides of the slot to its full depth so as to prevent the flow of paste mixture from the excavated region at the rear of the support into the forward clearance;
and motive means coupled to the outer end of said support supplying guidance and control to the support, supplying paste and fluid under pressure to said passages, and supplying energy to said cutting means.

3 more elements

Dependencies are inferred from the claim text.

Facts

Application: 05/604,055Filed 12 Aug 1975 · continuation in part
Priority: 16 Apr 1974
Granted: 22 Nov 1977
Term ends: Not estimatedThe source records don’t support an estimate.

Classification3 codes

E21C 41/26
Methods of underground or surface mining ; Layouts therefor: methods of surface mining ; Layouts therefor
E21C 25/60
Cutting machines, i.e. for making slits approximately parallel or perpendicular to the seam: slitting by jets of water or other liquid
E21C
Mining or quarrying