The invention of what are called mechanical tiles led to that of machines allowing of a large output.
The problem was also solved by Gilardoni, who, by means of some hints given to Jean Schmerber (1824-1895), a partner in the firm of Schmerber Brothers of Tagolsheim (Upper Rhine), suggested to him the idea of the press which bears his name, and of which the present presses are only variations.
This type of press (Figs. 390, 391, 392) consists of a shaft C geared to another shaft A, which carries the driving pulleys and two flywheels, B B. On the shaft A is fixed a steel five-sided tile press (Schmerber System).
Fig. 390. View from the Bolt Side.
Fig. 391. Front View.
Fig. 392. Side View. eccentric D, which acts on a slide E, also of steel, and placed in the mould-carrier F, which holds the upper mould G.
Below is another mould-carrier with five sides mounted on a shaft I, which is furnished at one end with a plate with five notches L, and at the other with a grooved pulley R. The plate L is kept fixed by a bolt K, which slips into the notches.
While the counter-mould G compresses the clay on the mould H, a workman placed behind the machine puts on a board the tile just pressed, and a second workman in front of the press places on one of the sides of the revolving carrier the slab of clay for the next tile. When the compression is finished, the mould-carrier F is raised by the arm P of a jointed lever, which is fixed to the shaft O, and the second arm N of which is set in motion by the eccentric M acting on the slide a.
When this movement is nearly completed, a little cam b comes to unlatch the bolt K, and at this moment the belt joining the fwo pulleys Q and R is stretched by means of a projection on the pulley Q, so that the shaft I begins to move, and continues until the bolt K, released by the cam b, falls back into a notch of the plate L. The lower mould-carrier has then described one-fifth of a circle, and another mould is now below the counter-mould G. The cam D, by means of the slide E, again acts upon the mould-carrier F, the descent of which becomes slower as the pressure increases, in order to allow the air and the excess of clay to escape from between the two moulds.
The work may be done with soft, firm, or hard clay according as the moulds are of plaster or cast-iron.
The shaft I rests, by means of a regulating screw d (Fig. 392), on safety plates which protect the supports in case of an accidental excessive pressure. A break acting on the felly of one of the flywheels allows of the machine being instantaneously stopped.
In the Boulet machine (Fig. 393) the principal parts are the same as in the foregoing machine, and its working is similar. The moulds are of plaster or cast-iron, according to the method of manufacture.
The Jager machine (Fig. 394) has no belt for moving the revolving mould-carrier, but the latter is provided with a wheel with curved segments which rub against a felly fixed to the large gear-wheel. This felly is interrupted for a certain distance, and in the hollow is a little rod perpendicular to the wheel, which, at a certain moment, enters a notch in the segmented wheel and drives it forward one-fifth of a revolution. The rod then frees itself, and the felly, rubbing against the segment, keeps it in its position.
Fig. 394. Five-sided Tile Press (Jager).
A similar arrangement is found in the Groke (Fig. 395) and Laeis (Fig. 396) machines. The former is fitted with a break for instantaneous stopping as in the Schmerber machine.
In the Lobin press (Fig. 397), the motion is communicated to the counter-mould by means of knee-piece cranks, and the intermittent rotation of the revolving mould-carrier is effected by a ratchet-work moved by jointed levers of which one end is drawn on by a rotatory motion. In this machine, as in the preceding ones, the movement of the counter-mould is slackened at the end of its course, and there is besides a double compression, as in the Joly machines.
The Chavassieux press (Fig.398) possesses a similar mechanism to the last for turning the revolving mould-carrier, but the counter-mould is moved by an eccentric.
Fig. 399. Revolver Press (Chambrette Belon).
The Chambrette - Belon press (Fig. 399) has this special feature, that the upper part is fixed and it is the revolving mould-carrier which is movable. The motion is effected by cams which cause successive compressions.