GB772776A - Hydraulic excavator - Google Patents

Abstract

772,776. Hydraulic-excavating apparatus. CRAGGS, J. H. June 14, 1955, No. 17055/55. Class 68 (1). In an hydraulic excavator for subterranean deposits accessible by the open pit method a nozzle assembly 14 is secured to the lower end of a casing 16 extending to the surface and a casing 10 and a plate 22 are disposed concentrically of and secured to the casing 16 and assembly 14 to form a manifold chamber into which liquid, preferably water, under pressure is admitted from a supply pipe 24. Said liquid passes from the manifold chamber through vertical passages in the annular upper part of the assembly 14 and is discharged upwards through nozzle 60 and downwards through nozzle 46. The downwardly directed jet from nozzle 46 breaks up the deposits and the suspension thus created is drawn in through radially directed ports 56 in the annular upper part of the assembly and urged upwards through the casing 16 due to the suction created about the assembly by the jet from the nozzle 60. A Venturi is fitted in the entrance to the casing 16. Nozzle 36 on a plate rotatable about casing 16 provides a jet for breaking down the side walls of the excavation formed by the jet from nozzle 46. The discharge casing has a dimensional capacity greater than that of the sum capacities of the nozzles 60, 46, 36 and the material excavated during any unit of time.