Patent GB-631803-A (GB)
Title: Method and means for the manufacture of elements moulded as hollow tubes and method for incorporating same in the construction of buildings
IPC: B28B1/093
Filed: 1946-08-13
Abstract: 631,803. Moulding concrete &c articles. TECHNIQUES MODERNES SOC. ANON. Aug. 13, 1946, No. 23950. Convention date, Oct. 17, 1945. [A Specification was laid open to inspection under Sect. 91 of the Acts, Nov. 8, 1946] [Class 87 (ii)] [Also in Group X] Long articles of concrete or the like having through cavities are made by casting the concrete around rigid tubular cores whilst transverse vibrations are imparted to one end of the cores. The vibrations are propagated in the form of waves throughout the length of the cores and are transmitted to the surrounding concrete, whereby the concrete is compacted and adhesion between the concrete and cores is prevented. The drawings show a machine for doing this, comprising a frame A carrying a mould base B, mould sides C and mould ends 16, 17. The mould base rests on the frame and may be pulled out of the machine leftwards with the moulded article thereon. The mould sides are movable outwardly, to free them from the article, by means of a hand lever 15<SP>1</SP>. The mould ends have five circular apertures for the reception of hollow cores H. The mould end 16 is fixed, but the end 17 is movable along the frame towards the end 16, being supported for this purpose by a carriage 18 having wheels 19 which run on rails 12. The end 17 may be raised from the moulding position, to enable the base with the moulded article to be withdrawn. The right-hand ends of the cores H are attached to a carriage G, which may be moved to and fro along the frame by means of a winch comprising a hand-wheel 20 and cable 21. The cores are vibrated by means of an electric motor I mounted on the carriage G, this motor rotating an eccentric mass y' via belt x and pulley y. The eccentric mass is journalled in a casing y' which is clamped by bolts v and section w to a clamp Z by which the ends of the cores are held. The mass y' may rotate at 8,000 r.p.m. Additional vibrators 23 act on the side walls of the mould. A vibratory smoothing device 22, mounted on a carriage running on the rails 12, smooths the upper surface of the concrete article and removes excess concrete therefrom, and may apply a coating to the article. In operation, with the cores initially retracted to the right but still engaged in the mould end 16, the end 17 is moved up to the end 16 and the wheel 20 is turned to engage the cores in the end 17. Then the cores and end are moved leftward to the moulding position, the base B and reinforcement are inserted, the end 17 is secured to base B by a latch 24, the motor I is started to vibrate the cores, and the concrete is cast. The manually-operated parts of the machine may be operated by hydraulic or electrically-operated means. The Specification as open to inspection under Sect. 91 comprises also the following matter. (a) (Fig. 3 Cancelled). A device for connecting the vibrator to the cores comprises clamping jaws a, b, carrying cradles i between which the cores are clamped. A shaft e, rocked by a handle f, carries eccentrics which bring the jaws together against the action of springs h. The vibrator (not shown) is connected to the device by means of a clamping band j secured to the lower jaw. The upper cradles i are secured to the upper jaw through a flexible washer k that is mounted with an initial tension in such a way that during the vibration '' the deformation stays below the elastic limit." (b) The device shown in Fig. 3 (Cancelled) may be used to vibrate any mould held between jaws. This subject-matter does not appear in the Specification as accepted.