摘要:
An improved trolley system section insulator having a main support insulator, end support insulators attached to trolley wires and an intermediate runner member. The runner member is formed of two spaced conductive portions which are attached to the main support insulator by studs extending upwardly through the main support insulator, the studs being electrically connected together at their uppermost ends, thereby forming 90.degree. changes in direction of the current paths which exist when arcs are formed. The path changes produce magnetic fields which tend to blow the arcs downwardly, protecting the insulator portions from arc damage.
摘要:
A female contact has at least one contact arm with an outwardly diverging tip end for guiding the tip of a male blade inserted into the contact. A contact arm abutment is mounted on a contact chamber sidewall and projects inwardly into the chamber. The abutment is aligned with an elongated contact arm of the female contact and is spaced outwardly from that arm to set the limit of acceptable outward contact arm deflection. A portion of the contact arm extending rearwardly from the diverging tip end is channeled to allow this end to clear the abutment when the contact is inserted longitudinally into the chamber from the rearward end thereof. The abutment limits outward displacement of the contact arm to prevent the overstressing of the arm by an engaging male blade and in a preferred embodiment, is formed as a unitary part of the pocket sidewall.
摘要:
A section insulator for insulating adjacent sections of contact wire of overhead power supply systems for electrified railway lines and the like is disclosed. The section insulator is interposed between separated ends of adjacent sections of contact wire. Strain plates are secured to the opposed ends of the sections and a strain insulator is secured to the strain plates above the level of the contact wires to maintain the tension in the contact wires. Spaced runners supported by the strain insulator extend between the contact wires, there being air gaps between the ends of the contact wires and the runners. A pair of diverging glider arms is secured to each contact wire section adjacent its end. The glider arms extend toward each other beyond the ends of the contact wire sections and overlap the ends of the runners, there being transverse air gaps between the diverging glider arms and the runners. The system thus provides a smooth under run from one section of contact wire along the diverging glider arms to the runners, then to the other pair of diverging glider arms and to the other section of contact wire. The insulator is supported by members extending vertically from the strain plates to a messenger wire, bridle, or other appropriate support. The section insulators can be adapted to use in ordinary catenary systems, compound catenary systems, ordinary direct suspension trolley systems, and as phase breaks for alternating current systems.
摘要:
An interface unit for a four wire telephone circuit includes an echo suppressor. A filter circuit is connected to the transmit line drop side to detect voice and SF signals and to selectively couple a regenerated SF signal and the voice signal to the line side of the transmit line. A passive filter is selectively coupled to the receive side to attentuate voice echo but bypass SF signals.
摘要:
A transmission line having a fixed characteristic impedance, e.g., 600 ohms, is coupled to a receiver through an input transformer working into a very small impedance, e.g., 10 ohms or less. As compared to a conventional arrangement, where an input transformer works into a load nearly as high as the characteristic impedance of the line, the new arrangement has considerably better low frequency response and delay distortion characteristics. The new arrangement permits a much smaller transformer to be used if desired while retaining favorable low frequency response and delay distortion characteristics.
摘要:
A one-piece housing for electrical terminals is disclosed, the housing being of the dead-front type and the enclosed terminals being connectable to external electrical circuits through apertures in the dead-front. The housing is generally formed of a dead-front or base member and two side casings, with web hinges joining these members as integral parts and allowing the side casings to pivot into opened and closed positions on the base member. Screw fasteners, located adjacent the ends of the casings remote from the web hinges, secure the casings together and clamp an electrical cord that is wired to the electrical terminals. Access to the enclosed electrical terminals is obtained, for wiring purposes, by opening one or both of the side casings. Locking lugs are formed integral with the side casings and base member to secure the casings to said base member, when the casings are closed, and provide a locking action in directions both longitudinal and lateral of the housing. These locking lugs thus remove both longitudinal and lateral stresses from the web hinges, and even permit continued use of the housing if the web hinges should fracture after repeated flexing.
摘要:
Disclosed is a method for "fingerprinting" electrical conductors connected to an electrical wiring device. Also disclosed is an electrical wiring device which allows one to reconstruct the connection of a conductor to at least one device terminal after the conductor is removed from such terminal.
摘要:
A ballast tester for HPS lamp circuits includes a body of insulating material, a base which fits the lamp socket, a single wire connected to the base and extending through the body forming a loop, and a hole in the body within the loop to receive a clamp-on ammeter. The ammeter measures short-circuit current, giving an indication of ballast condition.
摘要:
An emergency lighting circuit includes a lamp which can be energized by a battery-inverter circuit upon power failure. The battery is connected to the inverter circuit and the lamp by operation of a relay which is connected to the rectifier supplying charging current to the battery. The rectifier is connected across the line in series with a ballast reactor. The circuit can be used as emergency lighting only or the lamp can be employed for normal lighting purposes and switched to the inverter power when line voltage is interrupted.
摘要:
A reinforced cable having hauling, electrical and hydraulic lines. The cable has a substantially rectangular cross section and includes at least one internal support to protect these lines by resisting external compressive forces, and yet is bendable about one of its transverse axes for easy storage on and deployment from a drum. The internal support also protects the hauling lines from compressive forces applied longitudinally thereof by resisting radial displacement of the hauling lines. In one embodiment, the cable comprises an armor layer, a pair of engaged channels inside the armor layer, and a pair of corrugated supports inside the channels and fixedly spaced apart. The hauling lines, in the form of wire ropes, are located inside the corrugated supports, while the electrical lines are located inside the channels between the corrugated supports. The hydraulic lines can alternatively be located inside the channels between the corrugated supports, or inside the wire ropes. Any spaces inside the channels are filled by elastomeric material. In another embodiment, the cable comprises a rigid tubular support located between and engaging the wire ropes, and an armor layer engaging and enclosing the tubular support and the wire ropes. In this embodiment, the electrical conductor is located inside the tubular support.