Method and apparatus for rock excavation

Claim 3

A method as in claim 1 wherein the water being injected tangentially into said cylindrical cavity is prevented from entering the cavity during each impacting stroke of the piston type means.

Claim 4

A method as in claim 1 wherein excess water which could cause splash and otherwise interfere with the shaped jet of water is removed from the cylindrical cavity during the impacting of said annulus of water.

Claim 5

A method as in claim 1 wherein an air space is provided within the cylindrical cavity when used in an underwater environment.

Claim 6

Apparatus for producing an annulus of water repeatedly and forming same into a jet which is delivered at high impact velocity against a surface to be eroded, comprising: a. a high pressure cylinder housing having an open jet ejection end; b. a water inlet to said cylinder wherein water under pressure is pumped into said cylinder tangentially to form a rotating annulus of water which hugs the interior wall of the cylinder leaving a major portion therein as a clear space in which a jet is to be formed; c. a piston type reciprocating impactor head in the other end of said cylinder housing for impacting the rotating annulus of rotating water with a driving stroke at high velocity to force the annulus of water to converge upon itself along the longitudinal axis of said cylinder and form into a shaped jet which is then ejected from the open end thereof at high velocity; d. said impactor head as it travels within the cylinder to form a jet from the annulus of water and drive it from the cylinder being operable to cut-off and prevent water from entering the cylinder housing, and as it travels back being operable to allow water to again enter the cylinder tangentially; e. repeated reciprocation of said impactor head at high velocity being operable to form successive high velocity shaped water jets.

Claim 7

Apparatus for producing an annulus of water repeatedly and forming same into a jet which is delivered at high impact velocity against a surface to be eroded, comprising: a. a high pressure cylinder housing having an open jet ejection end; b. a water inlet to said cylinder wherein water under pressure is pumped into said cylinder tangentially to form a rotating annulus of water which hugs the interior wall of the cylinder leaving a major portion therein as a clear space in which a jet is to be formed; c. a piston type reciprocating impactor head in the other end of said cylinder housing for impacting the rotating annulus of rotating water with a driving stroke at high velocity to force the annulus of water to converge upon itself along the longitudinal axis of said cylinder and form into a shaped jet which is then ejected from the open end thereof at high velocity; d. said impactor head as it travels within the cylinder to form a jet from the annulus of water and drive it from the cylinder being operable to cut-off and prevent water from entering the cylinder housing, and as it travels back being operable to allow water to again enter the cylinder tangentially; e. repeated reciprocation of said impactor head at high velocity being operable to form successive high velocity shaped water jets.

Claim 8

A device as in claim 5 wherein means is provided for removing any excess water entering said cylinder housing that might interfere with the shaped jet.

Claim 9

A device as in claim 6 wherein said means for removing excess water is an interior circumferential flange within said cylinder near the open jet ejection end thereof and a controlled water outlet.

Claim 10

A device as in claim 5 wherein means is provided to form an air space within said cylinder when used in an underwater environment.