Method and apparatus for sinking shafts
AssigneeWirth Maschinen-und Bohrgerate-Fabrik GmbH
InventorJoseph R. Benjamin
Life of this patent
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Abstract
Disclosed is a method and apparatus for sinking shafts in which ring-like walling elements used as a shaft shoring are inserted into the shaft concurrently with the drilling thereof. The walling elements are held against rotation by a mechanism at the top of the shaft which sequentially inserts the walling elements into the shaft as dictated by the depth thereof as drilling progresses. The lowermost end of the lowermost walling element is supported on a bearing associated with the shaft drill bit.
Claims13
An apparatus for sinking shafts comprising a drill bit and a bearing associated with said drill bit for supporting of at least one walling section forming a shoring for the shaft and which is inserted into the shaft simultaneously with the drilling thereof characterized in that the bearing associated with the drill bit contains a plurality of bearing pieces of which each is movable from an operational position for supporting the walling section into a rest-position without contacting the walling.
An apparatus for sinking shafts comprising a drill bit and a bearing associated with said drill bit for supporting of at least one walling section forming a shoring for the shaft and which is inserted into the shaft simultaneously with the drilling thereof including a drill-rod system, a power swivel connectable to the upper end portion of said drill-rod system, and means for vertically moving the power swivel.
A method of drilling a shaft using a rotary drill bit wherein ring-like walling sections are sequentially inserted into the shaft one upon another simultaneously with the drilling operation to form a shoring for the shaft, the method including the steps of:
- peripherally loading the drill bit during drilling by supporting the undersurface of the lowermost walling section on radially inwardly retractable members located at the periphery of the drill bit,
- preventing the walling sections from rotating while allowing said sections to move down the shaft with the drill bit and
- radially inwardly retracting said members when drilling is completed to within the perimeter of the walling sections to permit withdrawal of the drill bit from the shaft.
Dependencies are inferred from the claim text.