Improvements in or relating to moulded hollow blocks for building purposes and machines for manufacturing such blocks

摘要

544,248. Moulding building blocks. MNDMAN, E. I. May 2, 1940, No. 7901. Convention date, April 28, 1939. [Class 87 (ii)] [Also in Group X] Blocks are moulded in a box 5 vibrated at the rate of 1,000-7,000 vibrations per minute by a belt-driven unbalanced rotary member 6a which causes the concrete mixture to pack down closely in the box in contact with a number of rows of fingers 7 rigidly fixed to the box and passing through apertures in the movable box bottom 9, the mass being pressed down by a plate 21 on a pivoted arm 20. The vibrator is then stopped, the plate 21 raised and the box bottom 9 with the apertured block thereon pushed upwards from the box by plates 16 on a block 15 carried by the plunger of a pneumatic &c. cylinder 13.