Abstract: Disclosed is a switching device for a tap changer comprising an input lever and an output lever rotatably attached to a shaft. The output lever is provided for making contact with a selected one of a first tap and a second tap. The output lever has a cammed surface at its base for securing a position of the output lever to make contact with the first tap and for preventing the output lever from rotating about the shaft. The device also includes a spring for pulling the output lever toward the input lever, and a clutch, rotatably attached to the shaft, which has a slot. A latching apparatus engages the clutch. The device further includes a pin which is fixedly attached to the input lever and disposed within the slot. The pin drives the clutch to engage the latching apparatus. In operation, after the input lever has been pulled away from the output lever by a predetermined angle, the pin drives the clutch to engage the latching apparatus, thereby freeing the cammed surface from the latching apparatus.

Abstract: A drive mechanism for a circuit breaker or power switch made up of at least one switching unit and comprising a biasing mechanism which can act upon the switching unit, with actuating mechanism for biasing the biasing mechanism, drive mechanism for driving the switching unit under the influence of the energy stored in the biasing mechanism, and mechanism for resetting the switching unit from the driven state. A coupling mechanism in the form of a movement-direction-dependent carrier mechanism is provided whereby the biasing mechanism is brought in its biased state into engagement with the drive mechanism for driving the switching unit and in the driven state of the switching unit the engagement of the biasing mechanism and the drive mechanism is released for resetting the switching unit without operation of the actuating mechanism, and the biasing mechanism and the drive mechanism act upon each other only in the direction of movement opposite to the biasing direction.

Abstract: A full double wall tank, primarily for underground fluid storage, which is simpler and more economical to construct than conventional full double wall tanks. An inner tank shell, preferably of steel, provides primary fluid containment and is the principal structural basis of the tank. An intermediate barrier layer is applied over the inner shell to define secondary containment space, and provides a base for application of a resin outer secondary containment tank shell which is preferably fiber-reinforced. Monitor sensor means is provided having access to the secondary containment space, preferably proximate the bottom of the tank. The barrier layer is preferably such as to provide a minimum of fluid-receiving secondary containment space for rapid and highly sensitive monitoring, and to provide cathodic protection for a steel inner tank shell.

Abstract: The switching device has a contact arm which is fixed on a shaft in the form of a thick-walled tube and is turnable between a closed position and an open position under the influence of a torsion rod spring. At one of its ends the spring is fixedly connected to the contact arm and at its other end to a percussion hammer. In the closed position the spring is arrested in tensioned condition by means of a latch. When releasing the latch for opening of the switching device, the spring energy is transformed to rotation energy in the hammer and is transferred to the shaft by impact against a projection on the shaft. In this way the contacts of the switching device immediately attain a great separation velocity.

Abstract: An improved contact mechanism for a switch is disclosed in which impact between contacts is reduced or moderated to minimize rebound of the contacts thereby to prolong the life of the switch. The contacts are sufficiently spaced apart from each other when the switch is in a stable open position, but when the switch is operated, the movable contact is first moved gradually to an intermediate position toward the fixed contact whereafter it is moved rapidly to the fixed contact over a thus reduced distance.