HOLE-FORMING DEVICE Russian patent published in 1998 - IPC

FIELD: construction industry; applicable in manufacture of reinforced-concrete articles with longitudinal hollows, for instance, panels, beams, pipes, etc. SUBSTANCE: the offered hole-forming device consists of body made of steel tube, oval in cross-section. Attached to tube shank are brackets which are located between pressed flexible hydraulic chambers connected by pipelines with hydraulic pulsator. The latter includes shaft with eccentric and hydraulic cylinders with pistons. When body is made of steel round tube, blades are secured to tube surface over its length. The device compacts concrete mix due to torsional vibrations of body relative to its axis by means of hydraulic pulsator, flexible hydraulic chambers and brackets. Blades installed on body of round cross-section ensure transmission of torsional vibrations from hole forming device to concrete mix. EFFECT: higher reliability due to absence of friction surfaces and bearing units. 2 dwg