Abstract:
The present invention relates to a safety apparatus for a machine such as a press brake. The machine has a first and a second machine part which perform a working movement towards each other. The first machine part has a leading edge in the direction of movement, and the leading edge defines a plane of movement. The safety apparatus has a plurality of first light barriers which run with the first machine part during the working movement, with the light beams of the first light barriers extending parallel to the plane of movement and being distributed in the region of the plane of movement in such a way that they run in advance of the leading edge with an increasing distance as viewed in the direction of the working movement. Furthermore, there is a control unit which stops the working movement in response to the first light barriers. There is also a configuration device, by means of which selected ones from the first light barriers can be deactivated at least for the duration of the working movement.
Abstract:
Light barrier apparatus generally features a light transmitter for projecting light across a region to be monitored to a light receiver. The light transmitter and receiver units can either be separate or can be combined in a single housing and used in conjunction with a retro-reflector for returning light from the sender to the receiver.In any of these arrangements the light transmitter and/or sender units incorporate photoelectric converter components 11, 12 and optical projection components 13, 14 together with electronic processing elements which enable interruption of the light barrier to be detected. The present arrangement features a housing 17 including at least one sealed chamber 15, 15', 15" containing solely the optical and photoelectric converter elements. These chambers are thus sealed against the ingress of contamination and moisture. The remaining elements of the electronic processing circuit are housed separately in a further chamber 16. The housing together with the fixed walls 18, 18', 18" of the sealed chambers 15, 15', 15" is usefully injection molded in one piece and preferably together with sighting aids 22.
Abstract:
A low-cost photoelectric machine access safety device is technically disclosed in the specification and drawings comprising an integral support structure supporting a retrodirective reflective (RDR) material facing an enclosed area which is to be guarded. A rotatable mirror causes a light beam from a reflex photohead to scan the guarded area. The RDR material reflects the light beam back along the transmitted path at varying angles of incidence. A photocell in the reflex photohead is activated to operate a control circuit to keep a control relay energized. Upon any interruption of the scanning light beam the relay is deenergized causing the accessed machine to stop. False operation preventing means prevents false operation when the light beam is scanning the portion of the support structure on which the rotatable mirror and associated apparatus is mounted. Fail-safe circuitry is also disclosed.
Abstract:
The apparatus includes a photoelectric sensor associated with a predetermined zone of a hollow glass article to be examined for faults. During one testing operation, the photoelectric sensor successively detects all faults in that zone and generates for each a fault signal whose value is dependent upon the characteristics of the fault. The fault signals are applied to a threshold circuit which generates an output signal only when the fault-signal value exceeds a threshold-signal level. The setting-up procedure involves performing at least one preliminary testing operation upon a preselected sample or standard article having acceptable faults. Each threshold-circuit output signal automatically results in a circuit adjustment which reduces by a predetermined amount the extent to which the respective fault-signal value exceeds the threshold-signal level. The preliminary testing operation is performed repeatedly, until the largest-value fault signal generated during one testing operation has a value slightly below the threshold-signal level, whereupon the testing apparatus has been properly set-up automatically. Thereafter, testing operations are performed upon articles whose eventual faults or flaws are not yet known to be acceptable.
Abstract:
A method and apparatus for providing output indications in response to the presence of an electromagnetic energy receptor within a predetermined distance of a glow discharge device the electrodes of which have a voltage applied thereacross at least equal to the maintaining voltage but less than the breakdown voltage, including an excitor for generating an electromagnetic field around the glow discharge device at a strength less than the ionization level but sufficient to ionize the gas when the electromagnetic energy receptor is within the predetermined distance of the glow discharge device.
Abstract:
A homodyne type radar for detecting intrusions into its field of radiation using the Doppler effect, working by pulses connected to an alarm device triggered in case of an intrusion. The output circuit of the pulse generator of the radar apparatus comprises a capacitor connected at the pulse frequency to a pulse generating and receiving circuit, the load variation of this capacitor controlling the alarm.The resistor is series connected to the emitter-collector circuit of a hyperfrequency transistor which is common to the pulse generating and receiving circuit.The cicuit connecting the capacitor to the alarm device comprises a low-pass filter and a step-apparatus.An oscillator controlling the pulse generating apparatus is also used to control a direct voltage to direct voltage converter when the power is supplied by a battery.
Abstract:
A system is disclosed for detecting, locating and monitoring floating objects and other subject matter at sea on another body of water or in other location of difficult access. A floating unit contains several retroreflecting elements and is placed at a location where detection is desired. For example, rescue or monitoring can be facilitated by detecting the floating unit from the air. Detection may include air borne signal apparatus such as a scanning laser beam or ordinary light source and air borne detection apparatus for detecting and analyzing a reflected signal.
Abstract:
A replica bridge sensing circuit, comprising an amplifier having inverting and non-inverting inputs, which are symmetrically connected to a generator through a bridge circuit that has replica elements in corresponding branches. Replica elements are defined as circuit components which because of identity of the manufacturing process, are nearly identical both physically and electrically. A nearly balanced replica bridge, so connected, between the input and the output of such an amplifier forms a Replica Bridge Oscillator (RBO) circuit. Non-linear elements are included in the oscillator circuit to stabilize the amplifier output amplitude and the phase angles between the inputs and output. Replica Bridge Oscillator operation is substantially immune to changes in environmental conditions and to changes in the power supply voltages. With replica sensor elements used in corresponding branches, the Replica Bridge Oscillator is a sensing circuit particularly well adapted for use in detection of small sensor impedance variations. When utilized for metal detection, such a sensing circuit exhibits improved sensitivity and stability over existing detection circuits and is particularly adapted for multiaxial operation.
Abstract:
A photo-electric light curtain for braking and terminating power to the ram of a press when an obstruction is detected in the curtain area uses an elongated fluorescent lamp as the light source. A number of spaced lens systems arrayed on the opposite side of the curtain area from the lamp focus on spaced points along the lamp. Fiber-optic strands connect the focal point of each of the lens systems with points arrayed about the stationary element of a circular commutator which are scanned by another fiber-optic element having one end affixed to a rotary commutator element and the other end feeding a photodetector. The output signals from the photodetector are processed to detect obstructions along the focal axis of any of the lens systems by fail-safe digital circuitry which provides an output when this blockage is detected for several cycles of the commutator. Counter circuitry, preset by manual switches, allows the system to ignore light blockages caused by permanent installations.
Abstract:
A means of optically recognizing the presence of substances on or within the walls of a transparent object or on the surface of a reflecting object by impinging a bar of light on the object and collecting the reflected or refracted rays of light by means of optical fibers and directing the light onto a photosensitive element connected to a circuit for using said information. The device disclosed is particularly suitable for inspecting glass jars to detect the presence of foreign material on the surface of the jars, such as "doping" or a mold release compound during manufacture, such as black spots which are undesirable because they have an unsightly appearance. The mold release is a necessary part of the jar manufacture process. The present system involves manual inspection of jars.