DE583814C - Safety device for presses and similar machines - Google Patents

Description

Safety device for presses and similar working machines Main patent 450 582 relates to a safety device for presses and the like Working machines to protect the operator against injuries, in which two Safety contacts - for example push buttons - arranged in this way and with the Drive are electrically connected that they during the dangerous movement process the machine should be held with both hands at the same time.

With safety devices of this type, where release or torque clutches used, was suggested by the additional patent 576: 222, another Arrange safety device by pressing the two safety contacts is switched on at the same time and the hands of the operator inevitably notes that a return movement into the danger zone during the danger time also is not possible after releasing the contacts. With the additional patent 564 266 becomes a protective grille when the two safety contacts are pressed at the same time Moved into the danger zone, which again automatically after the end of the danger time is withdrawn. After all, they are two-hand engaging devices for EYzenterpresses known in which the two control levers lock each other so that it is not possible to keep one lever switched on by wedging or tying it down to hold and thereby free one hand.

It has been shown that in the safety device according to the main patent 450 582 there is the possibility of permanently clamping one of the contacts or the like keep in working position so that the machine with the second free contact can be operated alone. With the hand that has become free in this way, he can Operators then get into the machine's danger zone during the danger time.

In order to remedy this deficiency, a device is provided according to the invention suggested that both contacts must return to the rest position before restarting the machine is possible. So will the operation of the machine with only one contact, while the second is permanently fixed. the Work machine is used in a known manner, for. B. by engaging a mechanical Coupling by means of an electromagnet, by electrically actuating a motor starter or similar devices set in motion, the circuit of the movement introducing electromagnet during that part of the working cycle; by doing there is a risk to the operator, only closed by actuating both contacts can be. Further details of the invention are described below.

The drawing illustrates an embodiment of the invention.

Fig. I shows the circuit. It's I. the electromagnet through which the machine is started. Through a cam 3 on the shaft of the Working machine, which also by a similar inevitably depends on the work cycle the machine-driven control element can be replaced, a contact 2 is controlled. With the coil of an electromagnetic switch is referred to, which the contacts 5 and 6 opens and closes. The push buttons 7 and 8 close and open the Contacts 9 and io or i i and 12. Arranged on the same shaft of the control disk 3 or inevitably coupled with it is another control disk 14th, which the Contact 13 actuated.

Fig.2 shows schematically the connection of the electromagnet T with the mechanical coupling 15 of a press drive 16.

The mode of operation of the device is as follows in Fig. I the switching elements are shown in their position when the 11 machine is at a standstill. Contact 2 is open, contact 13 is closed. The push buttons 7 and 8 are located in the rest position, so that the contacts 9 and io open and the contacts ii and 12 are closed. The electromagnetic switch. lies over the contacts LT and 12 are energized and contacts 5 and 6 are closed. Will now Push buttons 7 and 8 actuated and thereby the contacts 9 and io closed, then the electromagnet i is excited at the same time and the machine is started.

Although the contacts ii and T2 when pressing the two push buttons 7 and 8 are opened, the electromagnetic switch remains. still by line 17 via the now closed contacts 5 and 13 in the circuit. Will the snaps 7 and 8 released, the machine stops immediately as long as the contact: 2 is open is. Only at the end of the dangerous part of the machine's work cycle will the contact 2 is closed by the control disk 3. The machine then runs for as long the contact 2 remains closed, regardless of the position of the push buttons, because the electromagnet i- - is directly connected to the circuit via contact 2.

Immediately after contact 2 is closed, the control disk 14, the contact 13 is open, so that the electromagnetic switch 4 is de-energized and contacts 5 and 6 open, even if a push button is still in the working position stands. The machine can then only be started again in this way; that initially both push buttons 7 and 8 are released so that contacts i i and 12 the electromagnetic switch 4. is operated again and this the contact 5 and 6 closes again. Then a new operation can be started by pressing the Push buttons 7 and 8 are initiated.

Claims (3)

PATENT CLAIMS: i. Safety device for presses and the like Working machines according to J,? Atent 450 582 with two safety contacts, which during the entire duration of the machine's working stroke by the operator at the same time to be held with both hands, characterized in that to restart the machine both safety contacts after termination of the dangerous part of the Working cycle of the machine must be brought back to the rest position. 2. Safety device according to claim i, characterized in that an electromagnetic switch (q.) inevitably after the end of the dangerous part of the machine's work cycle is opened, thereby the circuit for the operation of the dangerous part of the The machine's work cycle is interrupted and only by returning both safety contacts (7, 8) can be closed again in the rest position. 3. Safety device according to claim i and 2, characterized in that the actuation of the electromagnetic Switch (4) is carried out by a control disk (14), which is dependent on the front Working cycle of the machine moves.