CH346100A - Plate press for working sheet material - Google Patents

Description

Platen press for working sheet material The object of the present invention is a platen press for working sheet material, for example paper or cardboard, comprising two platens between which the sheets are fine-tuned and held in place. Working position by means of gripper bars driven between two chains without. END.

During the operation of the press, the sheet transport control organs are subjected to considerable stresses, due in particular to the sudden and enormous accelerations and frictions to be communicated to the chains and their gripper bars.

These efforts can become dangerous in the event of a disturbance, that is to say if anything prevents the normal transport of the sheets held by the gripper bars. However, such accidents can occur, for example due to the fact that a bent or crumpled sheet or scraps of cutting or any other cause produce what is called a jam, liable to jam instantaneously a Bar and the chains which lead it.

The purpose of the press which is the subject of the invention is to remedy this drawback and is characterized by the fact that the driving of the pair of rollers with driving chains takes place by means of a friction coupling chosen in such a way that it disengages said chain wheels from their drive pulleys as soon as the resistive torque they oppose exceeds a predetermined value.

The attached drawing shows, by way of example, one embodiment of the press which is the subject of the invention. fig. 1 shows the pair of chain wheels driving the chain wheels and the friction coupling, half in view, half in axial section.

fig. 2 is to explain how the sliding of the coupling of fig. 1 can be used to cause the press to stop.

In fig. 1, it is assumed that a toothed sector (depicted) communicates intermittent rotational movements to a shaft 1, responsible for driving, in turn, a hollow shaft 2, carrying driving chain wheels 3 and 4 .

With the shaft 1 turns a sleeve 5, on which is arranged a ball bearing 6 and a perforated disc 7.

The perforations of this disc are distributed along the periphery of a circle and each contain a steel ball 8 of such a diameter that emerges from either side of the disc 7.

Two half-shells 9 and 10, forming a taut assembled at the chain row 3 and at the hollow shaft 2, take RTI ID="0001.0268" WI="9" HE="3" LX="1266" LY="2131 "> support on the ball bearing 6 and form a drum surrounding the disc 7 and the balls B.

In this drum are housed as many pairs of opposite hollow pistons 11, 12, as there are balls 8, which are partially capped by these pistons which enclose them, these pistons being axially pushed against each other by springs such as 13. The ends of the pistons pressing on the balls terminate in corresponding spherical housings.

It is clear that, if the shaft 1 drives the disc 7 and through it the balls 8, these will in turn drive the pistons 11, 12, when they are wedged, and with them the drum composed of the half-shells 9, 10, chain wheel 3, hollow shaft 2 and chain wheel 4.

If, however, the force which the balls 8 have to transmit through the intermediary of the pistons 11, 12, exceeds a certain value, as a result of a resistance exerted by the chain rollers 3 and 4, it is obvious that the aforementioned pistons will tend to slide over the balls, thereby compressing their springs 13.

We are therefore dealing with a friction coupling which, at a predetermined torque, depending on the number of balls, their diameters, the quantity of the pistons covering them and the power of the springs acting on the latter, will slip by separating the Trained Organs from the Coaching Organs.

But the guarantee offered by this coupling is not in itself generally sufficient, because it appears desirable and often essential that the press stop without impact from the first moment when a jam opposes its normal operation. This is why the example shown provides for the addition of a device capable of causing this stop and which is shown in more detail in fig. 2.

In this figure, there is the chain wheel 3 and the shaft 1, on which is fixed a pike 14 having a nose 15, through which it drives the sleeve 5 which surrounds it and screws, such as 16, make it possible to wedge very exactly, that is to say at an angle ensuring the chain wheel 3 entered by the sleeve 5, the immobilization positions bringing the gripper bars exactly to the various stations provided. .

On the chain wheel 3 are fixed two pins 17 and 18, each of which serves as a pivot for a simple lever 19 for the pin 17, and for a double lever 20 for the pin 18. A spring 21 seeks to push the lever 19 in the direction of the axis 1 and another spring 22 seeks, on the contrary, to raise the arm of the lever 20 located opposite the lever 19 and against the latter. But, at 23, the first lever 20 is against the first sleeve 5 and is thus stopped in this movement, the immobilization position corresponding to the equilibrium and to the normal operation of the press. In this position, two contacts which are located at 24 close a circuit, while a stop 25 of the lever 19 is located at a short distance from the free end of the groove of the lever 20 opposite to that urged by the spring 22. .

The circuit closed by contacts 24 serves to keep the press running, while opening it immediately causes parret.

The contact rings 26 of the hollow shaft 2 (see fig. 1) are connected by conductors not shown to the contacts 24 and thus allow the circuit to be closed during the rotation of the said shaft.

When the friction coupling, described above, comes into operation and separates the chain wheel 3 from the shaft 1, the sleeve 5, integral with this shaft, continues its movement with the latter, while said chain wheel 3 is slowed down, blocked, or can possibly continue its movement, even if the shaft 1 comes to a standstill. The normal direction of rotation allowed 6tant that of the arrow 27 of FIG. 2, if the chain wheel 3 is blocked and the sleeve 5 continues its movement, it is clear that at point 23 it will exert pressure on the lever 20, tending to cause it to oscillate in the direction schedule in relation to the drawing. In so doing, and the lever 19 being retained by a stop 28, the contacts 24 separate and the press stops.

In the 1st case of an action in the opposite direction, it is seen that the 1st point of contact 23 of the sleeve 5 with the 1st lever 20 moving away from this lever, the 1st spring 22 will cause it to oscillate in the 1st counterclockwise direction and its free end, Oppos6e to said spring, meeting stop 25, will raise lever 19 and cause it to rotate clockwise relative to the drawing, again having the effect of opening the circuit at 24 and stopping the press.

Thus, all the arrangements described so far will operate in such a way that the smallest angular differences between the rotations of the chain wheel 3 and those of the shaft 1 will have the effect of stopping the press.

Claims (2)

CLAIM Press with plates for working a mute in sheets, comprising two plates between which the sheets are brought and maintained in working position by means of gripper bars conducted between two endless chains, characterized in that the drive of the the pair of drive chain rollers is secured by the intermediary of a friction coupling chosen in such a way that it separates said chain rollers from their drive members as soon as the resistant torque that they oppose exceeds a predetermined value . 1. Press according to claim, characterized in that the drive member of the coupling consists of a disc having housings for balls distributed over a circumference and of diameter such that they exceed the profile of the disc. on either side of this last RTI ID="0002.0547" WI="12" HE="4" LX="1396" LY="1977">, these balls being, on each side, capped by hollow pistons , the Organs of each pair thus formed being elastically pressed against one another and the said Organs being integral with elements rotating with the pair of chain rollers. 2. Press according to claim, characterized in that contact pieces connected one to the driving element and the other to the driven element of the coupling, are arranged in such a way that, at each movement relative to these two elements, they modify the state of an electrical circuit, so as to cause the press to stop.