Method and apparatus for channel cutting of hard materials using high velocity fluid jets

Apparatus for channel cutting through or into a workpiece of relatively hard materials comprising:

• a main frame,
• means for propelling said main frame along the intended line of cutting on the workpiece,
• means on said main frame for producing a hydraulic fluid medium under high pressure,
• a plurality of nozzles each capable of concentrating fluid introduced to an entry port thereof into a high velocity, coherent fluid flow column emanating from an exit orifice which has a smaller opening than said entry port thereof.
• means for coupling the high pressure medium from said producing means to said nozzle entry ports,
• a manifold for retaining said nozzles so that the fluid flow columns therefrom simultaneously impinge on the surface area to be cut on the workpiece at spaced locations tranverse to the intended line of cut, and
• means attaching said manifold to said main frame in spaced relation to the area to be cut on the workpiece for directing the fluid flow columns from said nozzles in a fan pattern and in substantially normal orientation onto the workpiece area to be cut, the level of high pressure of the fluid medium from said producing means and the size of said exit orifices of said nozzles being selected for crushing and eroding the material of the workpiece impinged by the fluid flow columns while the rate of movement of said main frame along the intended cut line is selected for producing an elongated cut channel of a preselected depth, the sizes of said nozzle exit orifices being selected progressively larger depending upon the angular displacement of the fluid flow column produced thereby relative to a line normal to the surface area to be cut on the workpiece.

The method of channel cutting through or into a workpiece along an intended line of cut comprising the steps of:

• producing a fluid medium at a high pressure,
• concentrating the high pressure fluid into a plurality of fluid flow columns of a sufficiently high pressure for crushing and eroding the material of the workpiece when impacted in a direction substantially normal to the surface area to be cut on the workpiece,
• simultaneously impinging the fluid flow columns in spaced and substantially normal relation along a line on the area to be cut on the workpiece transverse to the intended line of cut,
• moving the fluid flow columns along a line parallel to the intended line of cut at a rate of speed for accommodating crushing and eroding of the workpiece material to a preselected depth, and
• continuously reciprocating the fluid flow columns along a line perpendicular to the surface of the workpiece by a distance corresponding to the intended depth of cut as said fluid flow columns are moved along each intended line of cut.