Water jet scarifying apparatus

Claim 1

A hydraulic scarification apparatus comprising a nozzle positioned at one end of a hollow shaft, a ball joint supporting said hollow shaft, high pressure pump means supplying water to said hollow shaft for delivery from said nozzle towards a surface to be scarified, de-gassing means positioned upstream of said high pressure pump, electronic control means operable to maintain said nozzle constantly at a predetermined height above the surface to be scarified, means for the removal of the scarified loose material and water from the region of impact of the water jet with the surface to be scarified, said nozzle being enclosed within a scarification head on which it is supported by said ball joint in such a way as to be freely movable within said scarification head, displacement of said nozzle being effected by nozzle displacement means including a linkage between said nozzle and said scarification head, said degassing means including a water container, a screen in said container, spray means operative to deliver water into said container, suction outlet means from said container leading to means for creating a partial vacuum in said container, said screen being positioned between said spray means and said suction outlet means whereby to prevent the passage of water droplets produced by said spray means, and level regulator means operating to control the flow of water to said spray means whereby to regulate the level of water in said container.