Abstract: A method of forming cooling ducts in the windings of a liquid cooled electrical transformer without adding permanent duct formers to the winding, and without requiring an additional manufacturing step to remove duct formers. Plastic tubes dissolvable in the liquid dielectric are utilized as the duct formers. Thermal siphon flow of the liquid through the tube openings when the transformer is energized dissolves the tubes and enlarges the cooling ducts to the outside dimensions of the tubes.

Abstract: A traction elevator system including elevator ropes, and hitch plates for terminating the elevator ropes. At least one of the hitch plates includes first and second vertically spaced, aligned support levels, with the rope terminations defining first and second complementary patterns, respectively, selected to reduce the maximum fleet angle by providing components thereof in the axial direction, with respect to the sheave axis, and transverse thereto, and by reducing the cross-sectional area occupied by the ropes at the hitch plate.

Abstract: A current differential pilot protective relay apparatus for multi-terminal high-voltage, three-phase alternating current transmission lines. The pilot protective relay system provides comparison, at each terminal of the transmission line, of the currents flowing on each phase of the three-phase transmission line at each terminal thereof. A novel scheme of summing the current-derived signals at one terminal reduces the number of receivers and transmitters necessary to send the local signal from each terminal to all of the other terminals. Instead, the current-derived signals are summed at one of the terminals and the sum signal is then transmitted to each of the other terminals.

Abstract: An escalator having a drive unit mounted in a supporting truss via a deflection beam. Load forces developed in the drive unit are transmitted from the drive unit to the ends of the deflection beam via elongated mounting base members which are not subjected to bending moments sufficient to cause harmful deflection and misalignment of the driving and rotating elements of the drive unit. The midpoint of a deflection beam is attached to the truss. Positioning devices adjustably orient the drive unit in the truss, and the midpoint connection of the drive unit to the truss adjustably selects the position of the drive unit along the longitudinal axis of the truss.

Abstract: A voice-controlled elevator security system. Access to an elevator system servicing a plurality of landings of a structure is controlled by comparing a voice signal of a potential user of the elevator system with stored voice signals of all authorized users. The comparison is accomplished by first digitizing the potential user's voice signal and comparing it, on a bit-by-bit basis, with a digital representation of the voice signals of all authorized users. Various criteria can be established for determining the number of binary bits that must agree to conclude that the potential user is an authorized user. Once this determination has been made, the authorized user can initiate car call signals for those landings to which the authorized user is permitted access.

Abstract: A padmounted transformer enclosure including a tank, terminal cover and sill which cooperatively define a composite structure having no pointed upper corners. The tank-terminal cover interface, and the terminal cover-sill interface, are both square, requiring no matching of curved surfaces.

Abstract: An elevator system including an elevator car having an electromechanical door restraint mechanism which includes a locked position which permits slight opening of the door by passengers for ventilation purposes, while preventing the forcible opening of the elevator car door beyond that point when the elevator car stops outside a predetermined allowable displacement zone adjacent to a floor level. Power supply failure deenergizes a first solenoid of the mechanism which causes the door restraint mechanism to assume its locked position. A capacitor, charged by the power supply before failure thereof, energizes a second solenoid to unlock the door when the elevator car is within an allowable displacement zone, and the closed door is moved slightly by a passenger towards its open position. Continued movement of the car door, beyond the predetermined point, returns the mechanism to the locked position, which now prevents complete closure of the car door.

Abstract: A strip coil winder for making a core-coil assembly characterized by feed rolls for feeding a conductive strip through a core window, drive rolls for receiving the strip on the other side of the window and re-directing the strip to the feed rolls, and winding rolls for wrapping the strip tightly in place on the core to form a helical winding.