Form with displaceable vibratory panel

Abstract

A modular forming system (10) configured for forming concrete box culverts is disclosed. The inventive system (10) includes displaceable panels for forming the concrete that are vibrated relative to stationary frames to compact the concrete enabling denser, stronger finished concrete to be formed with lighter weight, lower maintenance, longer lasting frames. The system (10) broadly includes a pallet (12), a core (14), a jacket (16), and a header (18). The jacket (16) encircles the core (14) and is supported on the pallet (12) and is operable to mold the outside circumferential surface of the culvert. The jacket (16) includes a plurality of modular sections (20-32) and each section includes a stationary frame (34), a displaceable vibratory panel (36), a plurality of spring assemblies (38-68) shiftably coupling the panel (36) to the frame (34), and a vibrator (70) coupled to the panel (36) for reciprocating the panel (36) relative to the frame (34). In a preferred embodiment, the panels are supported on the frames by a specified number of uniform springs generally determined by the formula: N=(32nπ2f2D3W)/(Gd4) wherein N=number of springs needed, n=number of active turns in each spring, π=22/7, f=frequency of vibration of the panel (Hz), D=mean coil diameter of each spring (m), W=weight of the panel (kg), G=shear modulus of the sprng material (N/m2), and d=wire diameter of each spring (m). Each of the panels is vibrated by an eccentric motor that is adjusted to vibrate the respective panel at or about a resonant frequency. In this manner, all of the panels vibrate synchronous in resonance, thereby providing optimum external concrete compaction.

Dependencies are inferred from the claim text.