Abstract: A plate heat exchanger, in particular an oil cooler for internal combustion engines, in a stacking mode of construction, provides conduits projecting toward one side for formation of feeding and drainage channels. Each conduit typically is provided with an edge bent inwards and running parallel to the base of the neighboring plate. The collar forming the conduit projects sufficiently far from the base of the plate that the edge projecting inwards can abut the base of the neighboring plate. This configuration reduces the heat exchange surface. To eliminate this problem, instead of collars with an encircling edge projecting only toward one side, collars projecting toward both sides are provided. Each of the collars is formed conically and engages, on stacking, into another of the collars. The collars are formed identically, but on plates which, when set on one another, are turned 180° with respect to the other, thus making simple soldering and simple handling possible.

Abstract: A liquid and gas impenetrable switch, especially for electrical surgical instruments, has two pairs of contacts spaced from one another. The movable contact element of each pair is arranged between the associated fixed contact element and a diaphragm. With elastic deformation, the diaphragm and movable contacts can be moved by the switch operating force into contact with the fixed contact elements. The diaphragm covers the movable contact elements and is supported by a rocker.

Abstract: A transfer film having a magnetic layer consists essentially of a substrate film, a parting layer and a transfer layer which is detachable from the said parting layer and is formed by one or more magnetic layers, and, on that side of the magnetic layer which faces the substrate film, after detachment of the substrate film, the surface-forming layer consists of a top layer which contains inorganic pigments in a cross-linked polymer matrix and has a thickness of from 0.2 to 5.0 .mu.m and a surface resistance of from 10.sup.-1 to 10.sup.-8 ohm/cm.

Abstract: A planar good electrical conductor part, having a connection lug connects to the outer conductor of a coaxial cable. The part has near its circumference an annular array of through-holes through which contact pins can be passed and brought into contact with the part. A central contact pin can be passed through a recess arranged approximately in the center of the part and can be brought into contact with the inner conductor of the coaxial cable secured to the part by the lug and aligned with the central recess.

Abstract: It is known in the art to characterize, by means of special bits in the time-division multiplex signal frame, transmission paths in a PCM transmission system which do not convey a useful signal, or to refrain from transmitting a signal through a non-occupied transmission path. To prevent the necessity of resolving the frame structure down to the bit plane for enabling recognition of the identification of non-occupied and undisturbed transmission paths, a digital signal pattern is used which is periodical, is distributed over the time-division multiplex frames and cannot be simulated by frame alignment of system alarm words nor by the useful information.

Abstract: Arrangement for producing and recognizing information identifying non-occupied transmission paths in a digital transmission system.It is known in the art to characterize, by means of special bits in the time-division multiplex signal frame, transmission paths in a PCM transmission system which do not convey a useful signal, or to refrain from transmitting a signal through a non-occupied transmission path. To prevent the necessity of resolving the frame structure down to the bit plane for enabling recognition of the identification of non-occupied and undisturbed transmission paths, a digital signal pattern is used which is periodical, is distributed over the time-division multiplex frames and cannot be simulated by frame alignment of system alarm words nor by the useful information.

Abstract: A gas-tight crossflow heat exchanger consisting of a metal casing with two gas inlet nozzles and two gas outlet nozzles, at least one installation cover on the top of the casing, a block consisting of a number of ceramic heat-exchange elements mounted completely accurately in cuboid form with gas ducts arranged in layers one above the other and running at right angles to each other, four side surfaces having gas-duct openings, and the bottom and top surfaces being free of openings, the heat exchanger further consisting of thermal insulation between the metal casing and the block of ceramic heat-exchange elements.

Abstract: An adaptive delta modulator must produce at its output a periodic 0-1 sequence when the input signal (w) to be coded assumes zero value. The delta modulator of the present invention is provided with a generator (GE) to produce a periodic 0-1 sequence which is transmitted to the receiver instead of the delta coded signal when the input signal to be coded assumes zero value. This generator (GE) is switched to the output line of the delta modulator at the instant at which the output voltage (Us) of a filter (IN) in the feedback path of the delta modulator, for determining the instantaneous quantizing unit of the delta modulator, assumes zero value. If this filter (IN) is implemented with digital components, the generator (GE) is triggered by the output pulses of a gate (G1) whose inputs are connected to the respective locations of the input signal storing means of the filter (IN). A delay line (V) prevents triggering of the generator (GE) at extremely short pauses in the input signal (w) to be coded.

Abstract: A data waveform modulates a carrier to produce a data-waveform-modulated input signal v, which is applied to the input of a delta-modulation transmitter of controllable quantization-step size. The delta-modulated output signal d of the transmitter is fed through a shift register, to the individual stages of which the inputs of a coincidence gate are connected. The output signal of the coincidence gate is transmitted through a narrowband filter tuned to a frequency f.sub.s equal to the symbol transmission rate of the data-waveform-modulated input signal v. The narrowband-filter output signal is utilized to control quantization step size.

Abstract: A torpedo has an acoustical system for detecting targets and directing the torpedo toward the target. An electric motor drives a cam that operates a switching arrangement that alternately changes the torpedo motor speed between fast and slow speeds. Upon sensing a target, the voltage applied to the motor driving the cam is increased to speed up the switching cycle and thereby shorten the duration of the slow and high speed intervals.