Abstract: A signal interpreting system for frequency-selective multi-frequency tone dialing includes a code tester and a code converter, and two serially connected delay means processing the output of said code tester and having an output controlling logic circuitry arranged in the output circuits of said code converter.

Abstract: Electric fuses having a helically wound fusible element are provided with simple, cost-effective sheet metal means performing the dual function of supporting insulating plates which, in turn, support the helically wound fusible element, and of establishing conductive connections between the ends of the helically wound fusible element and a pair of ferrules by which the casing of the fuse is closed.

Abstract: A miniature fuse for small current ratings and small voltage ratings has a casing of porous cellulosic material, a pulverulent non-fulgurite-forming arc-quenching filler, a fusible element of low fusing point metal having ends bent upon the outer surface of the casing and squashed by the pressure of terminal caps press-fitted on the casing, and bodies of a cured synthetic resin imparting dimensional stability to the ends of the casing, firmly affixing the terminal caps to the casing, and resulting in the formation of a conductively stable mechanical connection between the fusible element and the terminal caps.

Abstract: A method for assembling fuses having casings closed by plug terminals conductively interconnected by helically wound fusible elements. The fusible elements are wound around squirrel-cage-like structures involving extremely thin and extremely stiff metal rods. These rods are withdrawn from the fusible elements and drawn out of the casings of the fuses at such time when the pulverulent arc-quenching filler filled into the casings provides sufficient support for the fusible elements so that the support thereof previously provided by the aforementioned metal rods can safely be dispensed with. The small diameter of the rods minimizes the voids initially formed by their removal which, in turn, minimizes the tendency of the fusible elements to be somewhat displaced incident to removal of their temporary metallic supporting rods.

Abstract: A fuse for elevated circuit voltages is provided with an arrangement or array of gas-evolving beads intended to improve the performance of the fuse under major fault current conditions. The fusible element is wound around a space in the shape of a four-sided prism, each full turn including four quarter sections. The fusible element supports a plurality of beads of a gas-evolving material that are positioned on all four sides of said space and substantially equally distributed among the four sides thereof. Said beads are mounted periodically on said quarter sections of said fusible element in such a way that bead-bearing quarter sections of said fusible element alternate with equal numbers of non-bead-bearing quarter sections thereof.

Abstract: Tap-changing means for tapped transformers include thyristors for effecting tap-changes. Additional tap-changing means which include electric fuses, current-limiting resistors and a relay-controlled standby thyristor trigger system prevent the occurrence of dangerous short-circuit currents in case of malfunction of the principal thyristor trigger means. The circuitry further includes a pair of voltage bucking relays energized by a pair of voltage sensors responsive to the voltage prevailing between the taps of the transformer winding between which a tap-changing operation is intended.

Abstract: A device for closing and opening X-ray film holders is provided with a pressure plate and a flexible partition separating the device into a main compartment and an auxiliary compartment. Each of said compartments is provided with means allowing the particular compartment to be evacuated and to be exposed to air under atmospheric pressure, irrespective of the condition of vacuum and/or pressure prevailing in the other of said compartments.

Abstract: A d-c fuse having a clearing ability ranging from currents close to the minimum fusing current to major fault currents is provided with a wide ribbon fuse link having a matrix-like system of perforations. The fuse link is wrapped around gas-evolving rod means in such a fashion as to form a gap between the longitudinal edges thereof resulting in the formation of currents of arc-quenching gas evolving from said rod means and flowing transversely across said edges of said ribbon fuse link.

Abstract: A multiphase under load transfer switch of the Jansen-type for tapped regulating transformers. The main contacts and the switch-over contacts of the transfer switch are formed by vacuum switches. The vacuum switches are operated by a common drive mechanism for all of the vacuum switches of all three phases of the transfer switch. The required sequence of the operation of the vacuum switches is achieved by interposition of lost motion connection means between said common drive mechanism and pairs of aligned operating rods for pairs of superimposed vacuum switches. A special common drive mechanism for said pairs of aligned operating rods for operating pairs of superimposed vacuum switches includes a squirrel-cage-like system of helical compression springs which are loaded by pivotable cam means and operate, when subsequently expanding, said pairs of vacuum-switch-operating rods by the intermediary lost motion connection timing means.

Abstract: A transfer switch for load-tap changers of the Jansen-type is provided with a non-linear surge voltage protective resistor forming a shunt across two taps of a tapped transformer winding and arranged in such a way that a breakdown of the resistor does not result in a short-circuit across the section of the tapped winding situated between the two taps.

Abstract: A system for reading bar codes having characters formed by a plurality of bars and inter-bar spaces wherein each bar and each inter-bar space of a character signifies a bit of information is provided with means for detecting too many or too few single bar signals in a quantized character signal and for detecting and correcting sequence errors.