1862 London Exhibition: Catalogue: Class 7.: Bradley and Craven
1561. BRADLEY and CRAVEN, MESSRS., Westgate Common Foundry, Wakefield.
Patent plastic clay brick-making machine.
The ground allotted to this firm by the Commissioners not being sufficient for the display of their dry clay and other powerful brick-making machines, the above engraving represents the only one their space will allow them to exhibit.
Any material capable of being manufactured into bricks, can be delivered to this machine in the state of dryness it leaves the earth, which, without the addition of any water, produces a superior pressed brick (with many clays), ready for immediate delivery to the kilns for burning. This is the case with several machines working the gault clay in Kent, which comes from the earth so dry, that when made by the machine, the bricks are immediately wheeled into the kilns. The clay on being dug from the earth is delivered to the machine, which grinds and works it into a close, dense, well amalgamated mass, and fills it into the moulds with great solidity.
The action of the machine is as follows:—
One pair of the moulds (of which there are twelve in the face of the rotating table) receives the charge of clay at a time from the mill. During the moment that this operation is going on the table is stationary, and two other moulds that have been previously filled are being subjected to considerable pressure by pistons on the opposite side of the table to the mill, and two finished bricks that have been discharged by an inclined plane from the moulds, are delivered on to a creeper band by the action of the machine for removal to the kilns or sheds, perfect-pressed face bricks. Thus the only labour required is to supply the crude, fresh-dug clay to the mill, when the machine prepares, manufactures, and also delivers the bricks to the kiln men for burning.
This machine makes from 15,000 to 20,000 per day. Three of them are working at this rate for the Aylesford Pottery Company, near Maidstone; and others in this neighbourhood, as well as in different parts of the country, are giving general satisfaction. To save any risk or disappointment to purchasers, the patentees invite manufacturers to test their own clays in the machines previous to incurring any outlay; and they will give every facility for doing so, the only charge being for carriage or freight of clay, when prepayment has not been made. The importance of such trials will be appreciated by practical men. This machine is on the same principle as their well-known dry clay machine, but is not so large nor so powerful.
The result of extensive practical experience, gained in working these machines in all kinds of earth, fully proves the great superiority of forming the clay in moulds, over forcing it through dies, and cutting it with a wire. The advantage lies in the greater truth in the form of the bricks, and also in making them without any water. A still more important advantage is, that the manufacturer is enabled to work any kind of clay, from sandy brick-earth, to the strongest clays mixed with breeze or ashes and sand, to reduce it, neither of which could be worked satisfactorily with a die or cut smooth with a wire. Furthermore, it enables the manufacture to be carried on through all seasons of the year.
Price of machine subject to 1s. per 1,000 royalty: £250
Price of machine free from royalty, for export: £500
Illustrated catalogues of dry clay and other machines for the manufacture of bricks and tiles, with references to those at work, may be had upon application.