Abstract: Maintenance trip functions override the normal or specified trip functions of a low voltage circuit breaker to reduce pickup currents and/or time delays to effect faster trips, which reduces arc energy produced by faults during maintenance or testing on a live circuit breaker.

Abstract: A racking device performs a circuit breaker racking operation. The racking device includes a base with wheels and a brake to facilitate moving the racking device and positioning it with respect to a switchgear cabinet. An elongated tubular member extends substantially vertically from the base. A self-contained counter-balanced power module includes an enclosure having a pair of opposing openings for receiving the elongated tubular member, and a counterweight system for counter-balancing the power module. An actuator including a motor, a ball spline and a torque member moves a linkage assembly having an end effector with a negator spring that positively engages the circuit breaker. A switch module actuates the actuator from a remote location in order to move the linkage assembly and thus the circuit breaker to perform the racking operation from the remote location. Complicated field programming of the power module is not required.

Abstract: An auxiliary switch operator for a circuit breaker operates auxiliary contacts between open and closed positions. The auxiliary switch operator includes a hub which is biased to follow a pole shaft of the circuit breaker and follow the pole shaft when it rotates in a first direction to close separable contacts of the circuit breaker. A first spring mechanism biases the hub to follow the pole shaft when the pole shaft rotates in the first direction. When the pole shaft rotates in the first direction, an arm of the hub engages a rotatable shaft to drive an operating lever and operate the auxiliary contacts to the closed position. When the pole shaft rotates in the second direction, another arm of the hub recharges the first spring mechanism. A second spring mechanism biases the rotatable shaft and the operating lever toward a position corresponding to the open position of the auxiliary contacts when the pole shaft rotates in the second direction.

Abstract: An elongated retainer member pivotally mounted on the auxiliary contact operating mechanism of a drawout circuit breaker maintains a positive connection for the mechanism with the channel assembly of the motion transfer assembly which actuates auxiliary contacts mounted on the cabinet wall of metal-clad switch gear.

Abstract: There is proved by this invention a novel metal clad switchgear construction wherein the exterior walls are recessed to form areas disposed to provide ventilation shafts between adjacent units and increased access to the primary terminals.

Abstract: There is provided by this invention a novel switchgear shutter design employing curvilinear displaced shutter means which provide an entirely metallic grounded surface between the potentially live contacts and the front of the compartments. This novel shutter means is disposed to move to a safe and effective distance away from live electrical ports when the circuit breaker is moved into its normal operating position.

Abstract: An improved grid sleeve bulge tool designed for securing control rod guide tubes to sleeves brazed in a fuel assembly grid. The tool includes a cylinder having an outer diameter less than the internal diameter of the control rod guide tubes. The walls of the cylinder are cut in an axial direction along its length to provide several flexible tines or ligaments. These tines are similar to a fork except they are spaced in a circumferential direction. The end of each alternate tine is equipped with a semispherical projection which extends radially outwardly from the tine surface. A ram or plunger of generally cylindrical configuration and about the same length as the cylinder is designed to fit in and move axially of the cylinder and thereby force the tined projections outwardly when the ram is pulled into the cylinder. The ram surface includes axially extending grooves and plane surfaces which are complimentary to the inner surfaces formed on the tines on the cylinder.

Abstract: An improved grid sleeve bulge tool designed for securing control rod guide tubes to sleeves brazed in a fuel assembly grid. The tool includes a cylinder having an outer diameter less than the internal diameter of the control rod guide tubes. The walls of the cylinder are cut in an axial direction along its length to provide several flexible tines or ligaments. The end of each alternate tine is equipped with a semispherical projection which extends radially outwardly from the tine surface. A ram or plunger of generally cylindrical configuration and about the same length as the cylinder is designed to fit in and move axially of the cylinder and thereby force the tined projections outwardly when the ram is pulled into the cylinder.

Abstract: A compressive bumper assembly is disclosed for an electrically powered vehicle in which a bumper is resiliently supported in spaced relationship from the vehicle proper by means of a plurality of springs. The maximum displacement of the bumper from the vehicle is defined by means of inextensible members such as cables, chains or the like, which are secured to the bumper and to the vehicle. Levers are attached to the bumper at one end, the other ends having cam surfaces and being pivotally supported on the vehicle. Switches, electrically in series with the power supply for the vehicle, are provided with followers which are placed contiguously with the cam surfaces on the levers. The position of each follower determines the closed or open position of the associated switch. When the bumper comes in contact with personnel or any object, the bumper is compressed and the follower disciplined by the cam surface is displaced to open the proximate switch.

Abstract: The disclosure relates to a manual control handle for an electrically powered utility vehicle. The handle provides three functions for the vehicle: steering guidance, speed selection and directional control (forward or reverse). These functions are so designed into the handle that the operator is able to use the handle to control the vehicle without training and with a high degree of safety.

Abstract: An improved oil-pumping piston-assembly is provided for an oil-type circuit-interrupter to improve the interrupting performance during low-current conditions, having an improved hydraulic-dashpot action occurring during charging and discharging oil, incorporating, additionally, a "floating" piston design, and reducing the mechanical impulse forces exerted on the cylinder when high-current interruptions are made with an improved check-valve construction.The improved oil-pumping piston-assembly of the present invention is particularly adapted for the inclusion therewith of an auxiliary shunting separable-contact structure, which will, when desired, increase the current-carrying capability of the circuit-interrupter. Its inclusion, or exclusion, is optional, depending upon the current rating desired by the utility customer.

Abstract: A tank-type oil circuit-breaker has a pair of arc-extinguishing grid-structures disposed interiorly within the oil tank, each of said arc-extinguishing grid-structures having a pair of outwardly-directed horizontally-laterally-spaced venting ports, with the angular direction, or divergence between the two horizontally-spaced venting ports of somewhat critical angular magnitude.The construction is such that the two spaced venting ports on each arc-extinguishing grid structure collectively produce a resultant inwardly-directed jet force, which substantially counterbalances the outwardly-directed magnetic and mechanical forces resulting from the U-shaped line-current flow passing through the circuit-interrupter.The angular separation, or angular divergence provided between the two horizontally-laterally-spaced venting ports of each arc-extinguishing grid-structure falls within the range of angular magnitude of 80.degree. to 160.degree.. A desirable divergence range is between 100.degree. and 140.degree.

Abstract: A powered loading system is disclosed for loading and unloading a heavy load-carrying module onto a vehicle for transport. The module is supported for movement on casters and, additionally, it includes rollers and a slotted probe member. The transport vehicle for receiving the module includes ramp members for engaging the rollers on the module. A motor on the vehicle is coupled to a jackscrew which is attached to a movable block member. A hook member is supported on the block for displacement in an arcuate path normal to the ground plane. With the rollers on the module in position on the ramp members and deplacement impending, when the motor is actuated, the hook member engages and disengages with the slotted probe member for raising and lowering the module for, respectively, loading and unloading the module on the transport vehicle.