There have been great improvements made not merely in the construction of brick-machines during the last ten years. but also in their workmanship. A leading manufacturer claims that it is wholly a mistaken opinion that. because elay-working machinery must work in mini and grit, it chop ld be rough and coarse," and maintains that the details of such machinery should be "as thoroughly studied, and the design as carefully worked into shape, as though it were a Waltham watch or a Corliss engine. Though it may seem useless refine ment to work to templates with so much exactness on machinery that is to be covered with grease and dirt, and be exposed more or loss to the weather and all kinds of rough handling. yet it is decided economy, durability, and freedom from expensive delays, to justify this care and 'expense." The "...Vele Haren" horizontal Steam-l'otrer Briel:-.11aehine (Fig. l).—This is an example of a soft-clay or pallet-mud" machine. It is provided with a horizontal pug-mill, with a vertical pressing mechanism attached to the front, into which press-box the clay is forced by feed-wings on the tempering-shaft. The mold-ejecting carriage rolls on a mold-table (under machine), and is operated fnon a large press-gear by means of lever and connection shown on side of the machine. There are numerous features in the construction of this machine which are worthy of notice. The tempering-box has frame timbers, 8 in. X 8 in., strongly framed together, and is bound by three rods on each side, reaching from cud to end. rods also bind it front top to hot tom. At the front end, where the weight and strain are greatest. it is secured with strong iron braces and rodded in proportion. The bottom planks and side planks are removable. The rear end is a heavily ribbed casting. weighing 780 lbs., and is strong enough to stand any amount of back pressure that may be exerted at this point by the tempering-shaft. The lower front casting of the tempering-box weighs 700 lbs., is heavily ribbed on the inside, and has a babbitted bearing for the front end of the tempering-shaft cast on. with suitable oil-pipe east in. reaching to the top. Immediately above Is an upper front casting, which supports the steel crank-shaft, and which is held firmly in place by two side braces. and is securely held down against upward pressure of the press by heavy rods on each side of the crank. The tempering-shaft is 4 in. sq., with a heavy steel collar shrunk on at the shoulder next to rear-bearing. to give a large back pressure-wearing surface. On the rear end of the shaft is a heavy bevel gear, t3 ft. 10 in. diameter, 6 in. face, which is driven by a clutchpinion on main shaft. These gears have only to drive the tempering-shaft as the press is driven by pulleys. As many flat or pitched tempering-knives and feed-wings can be attached to this shaft as are needed to properly temper the clay and feed the press. The press box is 33 in. X 01, in. inside. The surfaces are planed and lined with steel plates. It will be noticed that the steel cross-head attached to the pitman, and which moves perpendicularly in the plunger standard, exerts its pressure squarely on a broad steel press-plate that fits in the pressure-adjusting notches. The effect of this arrangement is to assure a firm, square move ment of the plunger downward, and prevents liability to tilt and bring extra strain and wear on the guides. The pressing surface of the cross-head is 4 in. X 4+ in. The stroke of the plunger can be regulated by inches. from 81 in. to 10+ in., full stroke, and pressure remains on while the mold is being delivered; or, by removing the press-plate, all pressing is stopped while the machine still runs. That amount of adjustment should be enough to accommodate any degree of tempered clay. The means of relief in cases of stones or other obstructions consist in doors, shown in front of the press, which are held in place by springs, so adjusted that if an obstruction projects from any single brick that door will tly open and allow it to pass out, leaving the remaining five bricks in the mold perfect, or if the obstruction covers more than one brick it will open two or more doors and pass out. This arrangement prevents breakage and wear and tear on the molds. On the side of the machine just above the grip connection is a dash-pot with its plunger connected with the ejector-lever, which forms an air-cushion, to prevent jar on the return stroke. The mold-table is held in position by four large steel screws that work in heavy iron crossbeams. The ejector-carriage is of iron, with wood buffer strip on the front to protect the molds from wear. Its four rollers run on an iron track on table. The carriage has a quick return motion, which allows plenty of time to insert
the molds. Weight of machilte, complete, is about 14,300 lbs.. or a little more than 7 tons. In point of capacity, the machine is usually geared to make 13 molds per minute, which is 4,680 bricks per hour. For an output of 13 molds per minute the main driving shaft should run abnitt, 150 revolutions per minute. With still clay the power required for this output is about 25 horse. To produce 40.000 bricks per day requires a force of nine men and four boys.
the Chambers Brick-Machine (Fig, 2). manufactured by Messrs. Chambers Bro. & ('n.. of Philadelphia. Pa., is an example of an anger-class of stiff-clay machine. The clay is taken direct from the bank and dumped on the platform covering the machine at the side of a galvanized iron hopper that leads into tho tempering-ease of the machine, and mixed. when neeessary, with loam, sand, or coal-dust ; nod the requisite amount of water being added to temper the clay to the proper consistency, the MISS is shoveled into the hopper and falls into the machine. The hopper of the brick-machine proper is square, with circular corners, to prevent the clay from sticking in the corners, and is larger at the hot lmn than at the top, to prevent jamming of the mass. It enters the tempering-case at one side of its renter line. so that the clay in falling meets the revolving tempering-knives as I hey are coming This keeps up All agitation of the clay in the hopper, and tends to prevent clogging and an irreg ular supply of clay to the tempering device. A small east-iron roller is situated at the of the hopper, and just above the hue of tempering-kuives and at the side toward which the knives move. Against this roller the clay is thrust by the tempering-knives as they cut through the solid mass of line clay and lumps, and on to which the clay adheres : but as this roller turns around, say once in a minute, the impinged (lay is enrried within the path of the knives, and is curried id by them and tempered, thus effectually clearing the throat of the The totoperinl. pillion of the maehine consists of conics! case, in which revolves as horizfintal shaft into which are set siiirally, strong tempering-knives.
so that, as they pass through the clay, they move it forward. The clay being stiff, and not having much water on it. is not liable to slip before the knives, but is cut through and through, and thoroughly tempered, the air escaping back through the untempered clay, so that by the time the clay reaches the small end of the tempering-case it is ready to be formed into bricks.
On the end of the tempering-shaft is secured a conical screw of hard iron, which revolves in a hard-iron conical case, the inside of which is ribbed or fluted lengthwise, so as to prevent the clay from revolving in it, and is hard, to prevent wearing. The screw being smooth and very hard, the clay slides on it. thus becoming, as it were, a nut ; the screw revolving and not being allowed to move backward, the clay must go forward, sliding within the screw-ease. This operation further tempers the clay, and delivers it in a solid round column to the form ing-die, which (Fig. 3) is held within the steam-heated former-case. The great difficulty experienced in machines expressing plastic materials has been to make the flowing mass move with uniform velocity through all its parts. As the channel of a river flows faster than the shallow portions, or those near the banks, so does clay move through a die, the friction of the corners holding them back, while the center moves more freely. In the present machine this difficulty is overcome by the peculiar former." which is so shaped as to facilitate the flow of the clay to the corners. and retard it opposite to the straight sides of the die, the pro jections being much larger opposite the larger diameter of the die (Fig. 3). For very wide and thin bricks the resisting projection is omitted wholly at the short diameter of the (lie, or at the edge of the bricks, the spreading of the clay outward to the edge, rather than into the corners only. being facilitated. By this moans the angles of the bar of clay are re-enforced and made very solid and sharp, tints insuring square and well-defined corners to the bricks. The former" is secured to the screw-case by a hinge and swinging bolt, so that it may be quickly swung open for the removal of stones. This swinging bolt is secured to the case by pin of inst, sufficient strength to hold under normal conditions, and when undue strain comes from hard clay, etc., it yields, thus forming a saafegua•d against accidents arising from improper feeding.