GB197430A - Improvements relating to the construction of concrete piles or columns - Google Patents

Abstract

197,430. Hiley, A., and Le Bas, E., (trading as British Steel Piling Co.). Feb. 17, 1922. Steam hammers; cushioning reciprocating parts.-In constructing concrete piles according to the method described in Specification 179,699, [Class 68 (ii), Subaqueous buildings &c.], the concrete is deposited from a preparatory tube and is tamped and consolidated by vertical vibratory movements given to the tube by a hammer striking both upwardly and downwardly, the same hammer being preferably used for driving the tube. The hammer comprises a moving cylinder B with a stationary piston, steam being admitted above the latter to raise the cylinder which falls by its own weight and strikes the cap A<1> of the tubes A. To withdraw the tube, the hammer and the cap A' are hoisted up the girders of the frame A<x> in which they are guided by projections B<0>, A<0>, A<01>, to enable reinforcement bars and a charge of wet concrete to be introduced into the tube through an aperture a' in the casting A<3>. The hammer and cap are then lowered and links C, C are fitted on to the casting A<3>. Attached to the upper parts of the links are blocks C', C' serving as an anvil against which the cylinder strikes. The full stroke of the hammer is not used in this operation, and springs C<2>, C<2> are interposed between the links and the suspension ropes C<3>, C<3>. The lower ends of the links C, C are bolted to projections a<3>, a<3> on the casting A<3>, so that the upward impulses of the hammer striking the anvil blocks C<1>, C<1> are transmitted to the tube. Admission and exhaust of steam to the cylinder is controlled by a valve at the head of the stationary piston-rod b<1> actuated by a hand line D<1> through a lever D. In extracting the tube, an auxiliary check line D<2> connected to the lever D is operated by projections b<x> on the cylinder engaging a nut d' on the Jine D<2> to admit steam above the piston at a predetermined point during the down stroke of the cylinder to cushion the downward blow. The line D<2> may have a spring D<3> inserted therein.