Abstract: To achieve a safe and easy-to-handle connection, a fastening device for appending a piece of jewelry (1) to a jewelry clasp (2) or the like, which has a connecting piece (3) with a lug (6) attached in the vicinity of a surface indentation (4) for accommodating the end of a necklace or tie-on thread (7), is characterized in that of the lug (6) which is open at a point of separation (8) one of the end portions (9) on the side of the point of separation is fixed at the connecting piece (3) along the edge (5) of the surface indentation (4), and the other end portion (10) is bent up from the edge (5) of the surface indentation (4), that upon introducing a necklace or tie-on thread (7) through the expanded point of separation (8) the bent-up end portion (10) can be pressed down onto the edge (5) of the surface indentation (4), and that the clear inner width (a) of the lug (6) is smaller than the clear inner width (c) of the edge (5) of the indentation and smaller than the outer width (b) of the thickened end portio

Abstract: A latch for an article of jewelry, which comprises two magnetically attractable latch members, each latch member comprising a hollow body defining a cavity and open on one side, the hollow body having a circumferentially extending edge at the open side, a magnetic insert contained in the cavity, and a closure platelet covering the open side of the hollow body, the platelet being friction-fitted in the edge.

Abstract: A recording system for recording signals on a magnetic tape uses a recording apparatus and cassettes, each cassette containing a specific length of magnetic tape, and has a timer for setting time-preprogrammed automatic recordings.A detection unit determines the maximum time available for recording on a cassette placed in the apparatus and a comparator compares an output signal of the detection unit with a reference quantity which is a measure of the total time required for the preprogrammed automatic recording(s). When this required time exceeds the maximum time available for recording with this cassette, an alarm signal is produced. The cassette has marks which are sensed by the detection unit and which indicate the length of the magnetic tape in the cassette.

Abstract: A hold-back valve for single release air brakes includes a plug valve member in a chamber of a valve body and rotatable between at least two positions to establish paths of different resistance to flow between air inlet and outlet passages in the valve body. The plug has spherical central portion with a flattened surface and the spherical central portion is sealingly engageable with one end of a hollow cylindrical flexible packing surrounding the opening of the air inlet passage to the chamber in the valve body. The rotatable plug has passages therethrough to define two or three different flow paths when particular passages of the plug are connected between the air inlet and outlet of the valve body.

Abstract: The invention relates to a recording and playback apparatus for video signals including a drive shaft for driving a record carrier, whose revolution speed can be controlled by a servo system, and a switching device to ensure that a new recording without interruption follows an existing recording, said apparatus comprising a measuring and storage device for measuring and storing the difference in phase between the pulses supplied by the tacho-generator and the pulses scanned from the synchronizaton track which device is followed by a comparator, for comparing the stored measuring value with the reference signal for the servo system, which comparator if its input signals are equal supplies its output signal to the servo system as the measuring signal. Such a servo system prevents the occurrence of undesired phase shifts at the transition from the existing recording to the new recording.

Abstract: In a recording and playback apparatus the tachometer of the servo system for controlling the speed of the drive shaft uses a disc with a closed magnetizable track, which cooperates with an even number of equidistantly spaced magnetic heads connected to a direct voltage source in the playback mode. Each head successively magnetizes the track in an opposite sense. One of the heads scans the magnetizations stored in the track for supplying the input signal for the servo system during a recording. When a new recording is made which is to follow an existing recording, the magnetic heads are disconnected from the direct voltage source, and switching from the playback to the recording mode is effected by means of a switching device which can be controlled by the pulses scanned from a synchronization track on the record carrier.