Brick

We shall now proceed to describe the brick-making machinery invented by Mr. Leahy, and erected by him for the Patent Brick Company; it is represented in the accompanying figure. a is the main horizontal shaft in direct commu nication with the steam engine or other first mover; b is a hopper-formed vessel, technically termed the pug mill, in which the clay and other materials are tem pered and mixed up : it is for this purpose furnished with cross iron bars, or blades of steel; part of these are firmly fixed to the hollow vertical shaft c, and the remainder bolted to the sides of the pug mill, and they are so arranged, that those fixed to the shaft cut in as they revolve between the others. The clay is delivered into the hopper or pug mill by an endless chain of buckets (in the same manner as ballast is raised in the Thames) ; it is then cut up and tempered by the knives and bars in the pug mill, and gradually descending, it falls, or rather is forced by the superincumbent pressure upon the circular inclined plane d, which consists of a single thread or spiral turn of a very large screw, occupying the whole internal space of the lower cylindrical end of the mill, where it is exhibited in section. This screw or circular inclined plane is fixed to the central shaft passing longitudinally the hollow shaft, and a slow reversed motion is given to it, by means of an intermediate wheel acting upon pinions in the upper part of the frame. The blades on the hollow shaft, revolve in the pug mill at the rate of fifteen turns in a minute, grinding and dividing the materials much more completely than in the ordinary mode of brick-making. In this attenuated state the materials are forced upon the circular inclined plane of the screw, and as this slowly revolves in a contrary direction at the rate of five turns in a minute, It takes hold of the clay (by a peculiar adaptation not easily described), and forces it out of the mill, m a very compact state, into a recep tacle below : of this, one side is always in immediate contact with the moulds, and those two sides which are at right angles to the former side are closed by iron cheeks, between which the lever or forcing flap n acts by pressure, and, fitting closely, prevents the escape of the clay, so that it can only pass into the moulds. These moulds are placed round the periphery of a circular frame e made of flat iron rings, fixed upon bars or spokes, and turning upon a fixed shaft. There are twenty-five of these moulding boxes in one circle ; but as the frame e may be of any breadth, it may contain twice twenty-five or thrice twenty-five on the circumference of the cylinder, provided that the engine is capable of affording sufficientpower or force to cut or mould so many bncks at each revolution. moulding box is furnished with a false or movable bottom, to which rods are attached, for the purpose of pushing out the brick when moulded, and drawing back the bottom to its place to receive a fresh portion of the clay. The manner in which these operations are performed is extremely simple and ingenious. The ends of each of the moulding-box rods are bent at right angles, and an eccentric piece f is so fixed, that, as the moulds revolve, and at the moment that the surface of each is covered by being in contact with the clay, it gradually draws back the false bottom, and with it the clay, which is also urged on by the circular inclined plane d; and to render the bricks solid and compact, a powerful pressure is applied to them by means of the flap forcer a, to which a backward and forward motion is given by the thrtmting of a rod attached to a revolving crank. The moulding boxes, imme diately they are thus filled, are subjected alternately to the action of a steel scraper, which levels and smooths their surface, and is made to operate by the pressure of springs. The bricks, now completely formed and fast in their moulds, pass downwards in their revolution, which brings the ends of the rods under the operation of a cylindrical roller, with grooves made round it at equal distances ; into these grooves the ends-of the rods successively pass, which in their revolution force out the rods, and thereby push out the bricks from the moulds on to boards placed underneath to receive them. The bricks thus made are carried forward to the hacks or drying house, upon an endless web or chain i i, to which a continued motion is communicated by the revolution of the two polygonal drums or wheels k k placed at the requisite distance asunder. The upper part of the engraving shows a side elevation of the machine, and the lower part a section of it; and although these views serve to give a general idea of the construction of the apparatus, it has been impracticable to show the gearing by which the several motions are produced; we will therefore attempt to describe it as follows: Upon the horizontal shaft a (which makes 21 revolutions per minute,) is fixed a toothed, bevelled wheel, which drives a bevelled pinion on an upright shaft (not shown) • nearly at the top of this a spur wheel is fixed, which works into a pinion diced upon the of the hollow shaft c, which carries the knives or blades in the pug mill. Upon the upper end of this upright shaft is also fixed a pinion, which works into an intermediate pinion turning upon an axis. This intermediate pinion acts upon another pinion affixed to the internal shaft, communicatinga slow and reversed motion to it, and also the circular inclined plane affixed to it; at the lower end, on the main hori zontal shaft, is fixed a spur wheel m, which gives motion to the crank and to the flap forcer connected to it. o, in the separate figure, gives the form of the shelves comprising the drying apparatus,—Mr. Leahy proposing to dry bricks i either by flues or by steam, instead of ranging them in hacks exposed to the variations and inclemences of the weather,—by which means it is presumed that the bricks will be rendered dry enough for burning, either in kihis or clamps, in a much shorter time than in the common method, and the process may be carried on in winter as well as in summer. If drying by flues be resorted to, a drying house must be furnished with proper stages, and shelves must be pro-. vided. Around and across the lower part of these, flues framed either of bricks or cast iron are to be placed, through which flame or heated air is to be conveyed. In drying by steam, the vapour is conveyed from the boiler through cast iron pipes throughout the drying house, and boards are arranged upon stages (similar to those in the separate figure), so as to leave intervals between the rows of bricks, and to preveht their touching one another.

Nash'e Patent Brick-making Machinery. This invention, which we have now to describe, is the only one we believe that has yet been brought into suc cessful operation ;—owing probably to the circumstance of the patentee (who is a large tile and brick manufacturer at Market Rasen, in Lincolnshire,) having perseveringly applied that intimate knowledge of his art which can only be acquired by long practical experience. The leading features of Mr. Nash's mechanism consist m the application of separate or detached moulds of a par ticular construction to a series of mould boxes, which are consecutively brought into action, in the employment of heaters, placed in contact with, or contiguous to, the fresh bricks, during the process of their being moulded ; and in lieu of sand, which is generally used to prevent the adhesion of the bricks to the moulds, employing elastic absorbent substances, such as cloth saturated with water. In the subjoined engravings, Fig. 1 represents a front elevation, and Fig. 2 an end elevation of the principal parts of the machine. A vertical shaft a is made to revolve in the cylinder or pug mill b by any adequate force acting upon the bevelled wheel c. A number of broad steel or iron blades d d d are attached to the shaft a, their surfaces being set at such an angle as will cause them during their revolution to pass nearly in contact with the edges of two other sets of knives e e e fixed on opposite sides of the cylinder, by which means the clay and other materials with which the mill is charged are tempered and amalgamated, and then forced into the hopper f, fixed to the lower extre• mity of the pug milL This hopper is divided into two equal chambers by a vertical blade or knife, which separates the materials into equal portions, which are supplied to the moulds in a compact state. The moulds are lodged in rectangular cavities at equal distances in the periphery of two polygonal drums g h ; these cavities are marked 1 to 12. To one face or side of the drums are

attached two toothed wheels, gearing into each other so as to revolve in opposite directions when motion is communicated to one of them. These wheels lying at the back of Fig. I cannot be seen, but one of them is shown at i in Fig. 2. The moulds, after being filled with the plastic material, are pushed out from their recesses by means of pistons at on m, easily fitting the recesses, and sliding upon parallel rods fixed to the rims of each drum. To each piston is attached, by a short rod, a cross head, eliding upon the parallel rode, and having at each end small anti-friction wheels p p, which, by the motion given to the machinery, come in contact with a larger wheel q placed eccentrically, which thus raises the pistons, and the moulds which lie upon them are then removed by hand and emptied. During this latter process the emptied mould receiver will have passed over the centre of the eccentric wheel q, and the piston will be descending when the attendant places the emptied mould in its former situation, to be filled again from the hopper as it passes under it. Between each of the rectangular mould boxes are formed a series of wedge-shaped boxes, termed by the patentees " hollow sectors," into each of which is placed a red-hot iron, the object of which is to expel the superfluous moisture from the newly-formed brick, &c. in ordei that the manufacture may be conducted in the winter as well as the summer. These irons are heated in the kiln fires. The axes of the polygonal drums revolve in plummer-blocks, supported upon a strong frame but as the poly gonal drums revolve in close contact, the plummer-blocks are free to slide in grooves in the frame, and the wheels are kept in contact by the action of strong helical springs t, which press against the plummer-blocks, the other end of the springs abutting against a regulating screw. In the middle of, and underneath, the horizontal frame a, is fixed a knife u (supported in its place by a spiral spring), which separates the whole or a portion of the superfluous materials from each mould, as the latter passes over the edge of the former. As sonic redundancy of material may still be left after the operation of the knife u, the exposed surface of the moulds in motion undergoes a similar treatment from two other knives o v, fixed to the foundation plate w of the machine. A trough or cistern k k containing water, is placed under each of the drums, the lowest sides of which come in contact with a cylinder y, covered with strong coarse cloth or other suitable absorbent substance, which, as it revolves, takes up the water and delivers it to the moulds, as before mentioned. These cylinders are mounted on elastic bearings, and derive their motion from pillions on their axes, actuated by the toothed wheels on the drums. In the centre of the foun dation plate there is a cavity, or pit, for the reception of the superfluous clay or other materials, which are removed at pleasure. The pug mill has a door in it, for the convenience of cleaning it out when requisite ; and the whole of the upper part of the machine is supported by three columns z z a. The polygonal drums are driven by a set of wheels lying at the back of Fig. 1, and therefore in that figure shown by dotted circles. No. 1 is a band wheel, which drives the rest ; it is affixed to one of the columns, and has a pinion 2 attached to it, that drives a larger wheel 3, running loose on the shaft of one of the drums. This last propels another large wheel 4, fixed on the shaft of the other drum, gearing into each other; they are driven round together, but in opposite directions. Since our drawings of this machine were taken, we understand that the patentee has made some improvements in the arrangement of his driving wheel, which renders the action of the parts very steady and uniform. In case of negligence on the part of the boys, or other attendants of the machine, in not removing the bricks or tiles after the moulds containing them have passed the centre of the eccentric wheel, they fall back into their former position, and pass round to the place of delivery, as before, without any damage whatever being done to the machine. Having explained the general arrangement and operation of the machine, there remains to be described the construction of the detached moulds. Fig.3 represents a side view, and Fig. 4 an end view, of one of these. The en.ls of the mould 18, 18, are made of wood, plated at the edges with iron, and fastened on by screws, as seen in Fig. 3. The bottom 19 is also of wood, but cased in a strong frame of cast iron, and at its two extremities are jointed to the ends 18, 18, so as to open only a little way, for allowing the brick to separate freely from it upon inverting the mould. This effect is facilitated by lining the interior of the mould with cloth, which, although constantly in a wet state, admits air to pass through its interstices when the clay is forced into the mould, so that when the brick is afterwards forced out, the moisture of the cloth, and the spring of the confined air, delivers the brick uniformly clean, without the adhesion of any clay. It will be observed that the two ends 18 of the mould have each a cavity ; these cavities receive the fingers of the workman when he takes hold of the mould, which he afterwards mverts, drawing back the ends 18 at the instant, and pressing with his thumb upon the screw heads 21 21, the other ends of which are attached to a plate 22 underneath the cloth lining of the bottom, as shown by dots, causing the brick to be immediately disengaged. The two sides of the brick not included in the detached mould are formed by the par tition between the mould boxes and the hollow sectors. The forms and dimen sions of the detached moulds are varied according to the nature of the articles to be produced therefrom. For adapting the machine to make ties, or other articles of a greater length than a brick, two movable blocks, which usually lie inside the hopper, to contract its lower dimensions, are taken out. In the making of dram tiles, and other articles having cavities within them, jointed horses or cores are employed ; the plastic matter is forced around them by the action of the machine in the same manner as in forming a brick, and the sub sequent operations are also the same, except that in the removal or delivery of such tiles from their moulds, suitable adaptations are made to prevent their being pressed or even touched by the hand. The annexed Fig. 5 exhibits another arrangement employed by Mr. Nash for making flat tiles, flooring tiles, &c. of any required breadth and thickness. This cut only represents the lower part of the machine, the upper being the same as in the previously described apparatus. To the bottom of the pug mill is fixed a funnel•shaped hopper 23, the materials in which, after being forced through a mouth 24, formed of the required shape, are received upon boards 25, and when cut to the proper length, are removed to sheds for drying. In order to equalize the surface of the clay after it has come out of the hopper, a roller 26 turning in bearings on a curved arm, which is fixed to a hinge joint, gives tg the material any pressure that may be required, by loading it accordingly. The dotted lines 27, 27 in the same figure, exhibit another funnel-shaped hopper, for the purpose of making pipes or tubes, by means of a centre core 28, between which and the cylindncal continuation of the hopper, the material is forced by the action of the pug mill, and produces a tube, which, after having made a certain length of, is cut off, the tube being turned round, to render the inside smooth previously to its being removed. The patentee states that this machine may be used with either one or two horse power; that when used with one horse power, the product is about 700 per hour, or 8000 per day ; to do which requires the services of two men and eight boys, occasioning an expense not exceeding two shillings and sixpence per 1000. With two horse power employed, the production is double, or 16,000 per day; but the quality of the bricks, which the editor has seen, is equal to those which are usually finished by grinding the surfaces by hand. The saving of labour in the production is about two shillings per 1000; but the quality rendering them worth five shillings per 1000 more in the market, the advantage of making by the machine, where good bricks are required, is equal to seven shillings per 1000.