Erwin Sick Gmbh Optik-elektronik

Sick Ag

Gerhard Dieterle

Ingolf Braune

The invention relates to a method for securing a machine tool comprising a first tool part that carries out work movements in the direction of a second tool part in order thereby to carry out a machining process on a workpiece, wherein an optoelectronic sensor monitors a three-dimensional protected field between the tool parts in that light is transmitted along an open gap formed between the tool parts by means of a transmitter device and is detected by means of a receiver device which includes a matrix of light-sensitive elements, wherein the first tool part is stopped if individual light-sensitive elements or specific groups of the light-sensitive elements do not receive any light. In the method in accordance with the invention, relative positions between individual workpiece areas or measured values related to individual workpiece areas are determined from the signals delivered by the light-sensitive elements. The invention furthermore relates to an optoelectronic sensor by means of which the named method can be carried out.

Method for securing a machine tool and opto-electronic sensor for carrying out such a method

A monitoring apparatus for working machines (16) has a light curtain (11) at the entry side (14) of the working space (13). A rotational scanner (12) is also provided which scans at least the dangerous zone of the working space in a horizontal plane in order to also protect body parts of operators which enter into the working space (13).

Monitoring apparatus in machines

A safety circuit for a potentially dangerous machine monitored by light and which works in an operating cycle. A safety circuit is described which utilizes a series of relays each of which is switched from an energized to a de-energized condition once during each working cycle of the machine so that each of the relay contact also opens and closes during the working cycle. In this way each relay contact is tested. The relays are so interconnected that if one contact should stick it will interrupt the sequence and will ensure the potentially dangerous machine e.g. a press is rendered inactive. Circuits are given for both hand fed and automatic machines which are monitored by a light barrier or curtain. For the hand fed machine the cycle is initiated by the operator reaching through the light barrier to insert an object into the machine. For an automatically fed machine the test cycle is initiated by a switch automatically activated once per cycle.

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Simonswald, Germany

Gerhard Dieterle