Abstract: A safety switch for a guard device associated with a machine or a device, the safety switch has a switch housing, a switch head connected to the switch housing and having a drive device actuatable by a key insertable into and removable from the switch head, a switch actuating device which is displaceable counter to a restoring force into a position corresponding to a first switch position by an actuating force generated by the drive device and without this actuating force exerted by the restoring force assumes a position corresponding to a second switch position, a sensor detecting a presence and an absence of the switch head, and an actuator arranged in the switch housing and operating so that under a control of the sensor in the event of loosening of the switch head from the switch housing exerts a force on the switch actuating device in a direction of motion to the restoring force, that is equal to or greater than the restoring force, depending on whether the switch actuating device is to be held in a prev

Abstract: A compact safety switch comprises a housing having an axially sliding ram mounted therein. The lower end of the ram is in contact with an actuating rod of a switch, which is aligned with the ram. The upper end of the ram lies against a cam formed in the outer surface of an indexing wheel. A pre-tensioned helical spring surrounds the lower end of the ram for holding the ram in place. The indexing wheel is provided on one end of the cam with a radial notch for locking a key inserted into the keyway and at an opposite end of the cam with a resting notch. The safety switch further includes an interlocking mechanism having a stator located concentric to the ram and an armature integral with the ram. With the key inserted in the keyway, the armature is pushed out of the stator and the upper end of the ram is held in engagement with the resting notch.

Abstract: A safety switch has a key (1) which, when inserted into and removed from a key channel (9), forcibly rotates a cam plate (7) and so switches over the switch. The safety switch further has an interlocking device for the cam plate (7) which is disposed adjacent the latter, can be forcibly released by the key (1) when it is introduced into the key channel (9) and has at least one locking member (21) which can be displaced in translation and, in its locked position, engages in an interlocking manner with a housing disposed adjacent the cam plate (7). The locking member (21) can be displaced into the released position by the key (1) by means of an actuating member (15) which is moveable together with the locking member (21) and is integral therewith. The part of the actuating member (15) which projects into the key channel (9) in the locked position is connected to the locking member (21) by means of a material section which is laterally guided past the axis of rotation (6).

Abstract: In a high frequency interference suppression filter for a circuit to be connected to a conductor, particularly two-wire sensors having at least one inductor in series with the circuit to be protected from interference and having at least one capacitor parallel to this circuit, an ohmic series resistor is provided which is matched to the characteristic impedance of the conductor.

Abstract: A manually activated position indicator with electrical output signals includes a plurality of adjacent electrodes (S, Al-, Al+, Bl-, Bl+, Ax-, Ax+, Bx-, Bx+,Ay-, Ay+, By-, By+), which are electrically insulated from one another and are covered on one side by an electrically insulating layer (3) the side of which opposite said electrodes is provided as a support surface for a finger (4) of the user of said position indicator wherein said electrodes form at least three groups, and all of the electrodes (S) of a first group are connected to a voltage source (5) that delivers an alternating voltage (Us). The electrodes of the other groups are connected to a signal evaluating circuit, and at least one electrode of said other groups is arranged adjacent to an electrode (S) of the first group.

Abstract: A system for marking and identifying objects, particularly work implements such as tools and work piece holders required in manufacturing processes, which has modules (4) with electronically readable markings, which modules (4) are to be arranged on the objects (1) to be marked, as well as an evaluating device having at least one pick-up capable of reading the markings. Each module contains at least one oscillating circuit (5, 6, 7) to produce a characteristic resonant frequency or resonant frequency combination. The number of different resonant frequencies or resonant frequency combinations provided corresponds to the number of different elements in the selected characterizing code, and the resonant frequency or resonant frequency combination of each module (4) is selected according to one of these frequencies or frequency combinations.

Abstract: A circuit arrangement for protecting a remotely controllable semi-conductor switch which closes to interrupt an alternating current circuit in order to protect against an overload is disclosed in which a flip-flop is connected to control the operation of a current control circuit connected to the output of the semi-conductor switch in the event of an overload or short-circuit condition in the AC circuit. Provision may also be made for transient overload conditions, as well as providing a visual indication of the conducting condition of the semi-conductor switch.