An hand-operated safety switch with time delay (1) comprises a switching device (2) adapted to be anchored to a fixed part of the protection and provided with switching means (5) adapted to be connected to a plant to be controlled, an operating device (3) adapted to be anchored to a movable part of the protection for interacting with the switching means (5) upon the closing of the movable part. The switching device (2) comprises a locking mechanism (9) associated with the switching means (5) and adapted to selectively hold/release the operating device (3) and hand-operable unlocking means (10) operatively coupled with the locking mechanism (9) for unlocking the operating device (3) with a predetermined time delay with respect of the switching of the power supply circuit by the switching means (5). The switching device (2) has sensor means (13) operatively coupled with the switching means (5) for modifying their operative condition in function of an inlet signal. The operating device (3) also comprises a transmitter (14) adapted to send a proximity signal to be received as input by the sensor means (13) for controlling the switching means (5) when said transmitter (14) is place at a predetermined minimum distance from the sensor means (13). The locking mechanism (9) also comprises an inner passage (29) adapted to allow the passage of means for connecting the sensor means (13) with the switching means (5) avoiding the interference with the unlocking means (10).

An hand-operated safety switch with time delay (1) comprises a switching device (2) adapted to be anchored to a fixed part of the protection and provided with switching means (5) adapted to be connected to a plant to be controlled, an operating device (3) adapted to be anchored to a movable part of the protection for interacting with the switching means (5) upon the closing of the movable part. The switching device (2) comprises a locking mechanism (9) associated with the switching means (5) and adapted to selectively hold/release the operating device (3) and hand-operable unlocking means (10) operatively coupled with the locking mechanism (9) for unlocking the operating device (3) with a predetermined time delay with respect of the switching of the power supply circuit by the switching means (5). The switching device (2) has sensor means (13) operatively coupled with the switching means (5) for modifying their operative condition in function of an inlet signal. The operating device (3) also comprises a transmitter (14) adapted to send a proximity signal to be received as input by the sensor means (13) for controlling the switching means (5) when said transmitter (14) is place at a predetermined minimum distance from the sensor means (13). The locking mechanism (9) also comprises an inner passage (29) adapted to allow the passage of means for connecting the sensor means (13) with the switching means (5) avoiding the interference with the unlocking means (10).

A front end for an inductive proximity sensor includes a coil for detecting an approaching metal object and a circuit board, wherein the coil is designed as a circuit board coil disposed in the circuit board, wherein a metal influencing element which is disposed in or on the circuit board has an opening to receive at least one electrical connecting element, wherein a through connection of the circuit board to an electrical connection plane, which serves for electrical connection of the circuit board to a control electronics of the proximity sensor, is made by the at least one electrical connecting element.

A method of manufacturing a housing and a housing for an inductive sensor having at least one sleeve-like housing part and at least one beaker-like end cap for a sensor element, wherein the beaker-like end cap, wherein the end cap is composed of plastic, wherein the end cap is arranged in the sleeve-like housing part, wherein the end cap has a peripheral annular pressing surface that has an excess size with respect to an inner diameter of the housing part along an outer diameter of the sleeve-like section so that a press fit is formed between the sleeve like housing part and the end cap, and wherein a jacket-like outer surface of the sleeve-like section of the end cap does not have a step that projects beyond the inner diameter of the sleeve-like housing part.

A safety switch with detection of the end-stroke of the unlocking mechanism adapted to supervise a safety access of a machine or industrial plant comprises a switching device (2) adapted to be associated to the fixed part of an access to be supervised and having switching means (5) adapted to be operatively connected to one or more control and/or service circuits of the plant for the control thereof, an operating device (3) associated to a movable part of the access to interact with the switching means (5) at the time of opening/closing of the access for opening/closing of one or more circuits, an unlocking mechanism (13) housed in the switching device (2) and having an unlocking pin (14) adapted to translate with maximum predetermined stroke from a blocking position of the access to an unlocked position to determine the opening of the switching means (5), means (17) for the detection of the stroke of the unlocking pin (14) comprising a first detector (18) adapted to detect the start of the stroke of the unlocking pin (14) and a second detector (19) adapted to detect the end of the stroke of the unlocking pin (14).

The invention relates to an inductive proximity switch. The object of the invention to present a very simplified inductive position sensor, which can be reliably used for detecting a zero crossing of its output voltage when a target moves by will be solved by an inductive proximity switch comprising a transmitter coil, a receiver coil, an integrated circuit for excitation of the transmitter coil and a signal processing unit for processing a received signal from the receiver coil, wherein an oscillator excites a resonant circuit comprising the transmitter coil and a parallel capacitor for inducing a voltage in the receiver coil, wherein the receiver coil comprises two symmetrical segments with opposite orientation that are connected in series, wherein the transmitter coil surrounds the segments of the receiver coil or the transmitter coil is surrounded by the segments of the receiver coil.

A pulse generator comprises a mounting to hold two bodies in proximity to each other. Two magnetic elements may be movably placed in the mounting, and the magnetic elements will align with each other in one of two stable states. A coil surrounds the magnetic elements in the mounting, and a force application device applies a force to the first magnetic element to cause the first magnetic element to break the current alignment and thereby make the first and second magnetic elements realign to the other stable state. The movement of the magnets generates a pulse in the coil which may be detected by suitable circuitry and used. The device may be used inter alia to count rotations or linear movements, or to provide switching or remote control without the need for a separate power source.

A pulse generator comprises a mounting to hold two bodies in proximity to each other. Two magnetic elements may be movably placed in the mounting, and the magnetic elements will align with each other in one of two stable states. A coil surrounds the magnetic elements in the mounting, and a force application device applies a force to the first magnetic element to cause the first magnetic element to break the current alignment and thereby make the first and second magnetic elements realign to the other stable state. The movement of the magnets generates a pulse in the coil which may be detected by suitable circuitry and used. The device may be used inter alia to count rotations or linear movements, or to provide switching or remote control without the need for a separate power source.

A method can include in a first phase of a sensing operation, controlling at least a first switch to energize a sensor inductance; in a second phase of the sensing operation that follows the first phase, controlling at least a second switch to couple the sensor inductance to a first modulator capacitance to induce a first fly-back current from the sensor inductance, the first fly-back current generating a first modulator voltage at the first modulator capacitance, and in response to the first modulator voltage, controlling at least a third switch to generate a balance current that flows in an opposite direction to the fly-back current at the first modulator node. The first and second phases can be repeated to generate a first modulator voltage at the first modulator capacitance. the modulator voltage can be converted into a digital value representing the sensor inductance. Related devices and systems are also disclosed.

An inductive sensor device has a coil arrangement and sensor electronics for determining a longitudinal position of an at least partially electrically conductive and/or magnetically polarizable object moveable at a distance from a device end face along a device sensitive axis. The arrangement has a substantially planar exciting coil for producing an alternating magnetic field for inducing eddy currents and/or magnetic polarization in the object and a first substantially planar receiving coil substantially parallel to and overlapping the exciting coil. The coils are substantially parallel to the end face. The sensor electronics determine at least one parameter of an exciting coil electrical signal, which is variable owing to an inductive backward effect of the object, at least one parameter of a voltage inducible in the at least first receiving coil based on this effect, and the longitudinal position from the determined signal parameter and the determined voltage parameter.