Abstract: An edifice such as a sports stadium is adapted for open use during good weather as well as for covered use during poor weather by having at least one movable roof member. Each movable roof member includes a transport mechanism that is constructed and arranged to permit the roof member to move in a predetermined path with respect to the underlying structure of the edifice. The transport mechanism includes structure for supporting both ends of the roof member, which bridges an otherwise open area of the edifice. In order to permit some flexure and movement of the roof member with respect to the underlying edifice, as will inevitably occur as a result of natural forces such as winds, orientation structure is provided for maintaining the transport mechanism in a predetermined orientation while simultaneously permitting a limited amount of movement of the roof member in a direction that is nonparallel to the predetermined path of movement.

Abstract: A solid state motor starter, commonly referred to as a soft starter, is constructed in a manner to be easily manufacturable while at the same time combining all the required components in a relatively small package. A solid state power switch is clamped between a pair of bus bars in an offset manner to accommodate a discrete switching relay mounted in an inverted manner between the line input and the bus bar in communication with the load outputs. When in a motor run mode, current is shunted away from the solid state power switching device and through the switching relay, a substantially linear current path is achieved to reduce power loss and heat buildup. The arrangement allows for a heat sink mounted to one of the bus bars with adequate spacing between the heat sink and the discrete relay for insertion of a cooling fan. Current sensing is achieved with a Hall effect sensor mounted to the bus bar in a small current sensing region that is created by having a pair of slots in the bus bar to direct current.

Abstract: A motor starter thermal-compensation control is disclosed in which an ambient temperature sensor is positioned to sense ambient temperature and provide an ambient temperature signal in a motor starter. Additional temperature sensors are mounted in thermal communication with each bus bar in a motor starter and to monitor the temperature of each pole. A microprocessor is connected to each of the temperature sensors and periodically receives the temperature signals to monitor change in operating temperature of the motor starter. The control adjusts the output of the motor starter based on the change in the operating temperature so as to maintain a constant output as the ambient temperature increases, or the internal resistance of the device increases with temperature increase. In order to adjust the output, the system increases the FLA ampacity to compensate for the temperature increase.

Abstract: A motor starter control is disclosed in which an ambient temperature sensor is positioned to sense ambient temperature and pole temperature sensors are used to sense each pole temperature in a motor starter. A microprocessor is connected to periodically receive the temperature signals and monitor change in operating temperature of a motor starter system. The microprocessor models cool down characteristics of the motor starter system and compares currently acquired ambient and pole temperature signals to the modeled cool down characteristics and determines whether the motor starter system is cooled to a safe start temperature. The control ensures that a maximum number of starts per hour is not exceeded and prevents attempted starts that not only waste energy, but further prolong time to a successful start.

Abstract: An alternator regulator controls both output voltage and output current, limits input drive power and torque, and maintains output power within a prescribed range while operating over a wide ambient temperature range and shaft speed range. Voltage, shaft speed, and temperature signals are monitored, and the results are processed to determine the output current and to control the output power without exceeding the programmed limits for output voltage, output current, temperature, output power, drive power, torque, and shaft speed. This provides a predictable output power characteristic for the alternator and it eliminates high input drive power and torque excursions that occur at low temperature and certain shaft speeds. If programmed limits are exceeded over a specified interval, and the alternator does not respond to the control changes imposed by the regulator, the regulator will turn off the alternator's field current, activate an alarm circuit, and set fault codes.

Abstract: An apparatus for use in sensing electrical current in a conductor includes a flux concentrator and one or more magnetic flux sensors. The flux concentrator includes main sections which are formed of a magnetic material. One or more intermediate sections, formed of a nonmagnetic material, extend between the main sections of the magnetic flux concentrator. The main sections and intermediate section of the magnetic flux concentrator cooperate to at least define an opening through which a portion of the conductor extends.

Abstract: A magnetic flux concentrator shield is disclosed for use with magnetic flux sensors in an overload relay for multiple pole electromagnetic contactor applications. The magnetic flux concentrating shield has slotted layers of laminated members. The layers have a series of pole shielding slots which concentrate magnetic flux generated by conductors carrying current through conductor apertures in each layer. Magnetic flux sensors are positioned within air gaps within each pole of the shield. By shielding the generated magnetic flux from reaching the magnetic flux sensor of another pole, the pole shielding slots minimize cross pole magnetic flux sensor interference.

Abstract: A motor starter temperature protection control in which an ambient temperature sensor is positioned on an inside cover of the motor starter to sense ambient temperature across the power poles and heat sinks and provide an ambient temperature signal indicative of the ambient temperature in the motor starter enclosure. A power pole temperature sensor is positioned in thermal communication with each power pole and produce pole temperature signals indicative of the temperature of each power pole. A microprocessor is connected to each of the temperature sensors and receives the ambient temperature and the pole temperature signals to control the motor starter operation based on the temperature inputs. The microprocessor is programmed to periodically monitor the ambient and power pole temperature signals and compare these signals against a fan-on limit, and if the signals exceed the fan-on limit, the control turns on the internal fans of the motor starter.

Abstract: A solid state motor starter, commonly referred to as a soft starter, is constructed in a manner to be easily manufacturable while at the same time combining all the required components in a relatively small package. A solid state power switch is clamped between a pair of bus bars in an offset manner to accommodate a discrete switching relay mounted in an inverted manner between the line input and the bus bar in communication with the load outputs. When in a motor run node, current is shunted away from the solid state power switching device and through the switching relay, a substantially linear current path is achieved to reduce power loss and heat buildup. The arrangement allows for a heat sink mounted to one of the bus bars with adequate spacing between the heat sink and the discrete relay for insertion of a cooling fan. Current sensing is achieved with a Hall effect sensor mounted to the bus bar in a small current sensing region that is created by having a pair of slots in the bus bar to direct current.

Abstract: An electromagnetic starter with an overload relay having magnetic flux shielding is disclosed for use in industrial contactor applications. The starter includes a multi-pole DC controlled contactor which is interlockingly coupled to an overload relay. The overload relay has a simplified interlocking connection to the contactor, which when made, corresponds to an abutting electrical connection between the contactor and the overload relay also being made. The contactor further has a guiding pin that promotes even contact closure within the contactor.

Abstract: A plate pivotally mounted to a padlock hasp adjacent a reciprocally movable operator handle is pivotable from a stored position to one covering the opening of the hasp, the plate having a hole aligned with the opening and smaller than the opening to receive the shackle of a single, scissors-type safety lockout and maintain the shackle in position to block movement of the operator handle to an operated position. The hole is preferably rectangular to conform to the flat, thin shape of the safety lockout shackle to maintain the shackle properly oriented. An additional round hole for a smaller diameter padlock shackle may be provided in said plate.

Abstract: A flexible electrical connector is attached to a movable contact finger and a stationary termianl by placing the components in a work chamber and positioning a first end of the flexible connector against an attachment surface of the contact finger, preferably in a perpendicular orientation. After evacuating the work chamber, the output of an electron gun is directed toward a joint formed between the flexible connector and the contact finger. The electron beam forms a weld zone which fuses the the flexible connector with the contact finger without degrading the flexibility of the connector or the mechanical strength of the contact finger. A second end of the flexible connector is positioned against an attachment surface of the stationary terminal, such as in a parallel orientation, and attached in a similar manner.

Abstract: A switch has contacts constructed so that an electro-dynamic force is created by the current flowing through the switch which tends to maintain the switch in a closed state. This force counteracts other electro-dynamic forces which tend to open the switch. The contact design is particularly adapted from use in a single pole-double throw switch having a contact arm that is movable between two fixed contacts. The electro-dynamic force compensation exists between the contact arm and whichever one of the fixed contacts the contact arm is against. The fixed contacts also include arc runners so that any arc that develops as the contacts separate eliminates electro-dynamic force which tends to maintain the switch in a closed state.

Abstract: An automatic electric load transfer switch incorporates an over-the-center spring mechanism to operate switch contacts. The spring mechanism has a first position at which the electric load is connected to one electricity source and a second position at which the load is connected to another electricity source. The spring mechanism is driven by a solenoid activated cam shaft. An apparatus is provided for halting the movement of the spring mechanism at a position intermediate the first and second positions at which the load is not connected to either electricity source. The halting apparatus is releasable so that the spring mechanism can continue its movement between the first and second positions.

Abstract: A free-standing rolling book comprises plural sheets, bound along one marginal edge. In the preferred embodiment, the book cover includes printed matter depicting a wheeled vehicle having wheel wells disposed adjacent the bottom edge of the book. Respective wheels are rotatably cantilever mounted at each of the wheel wells. The dimensions of the sheets and the wheel span of the wheels are selected such that the wheels support the sheets in a free-standing position so as to permit the book to roll without external support. The wheel span should be at least two-sevenths of the distance between the center of gravity of the book and the wheel-supporting surface, and, in the preferred embodiment, is one-seventh of the book's height.

Abstract: A digital odometer having a mechanical memory in the form of an encoder supplies binary data to a logic control and memory which may be a microprocessor. Both total distance and trip distance are stored in memories in the logic control and memory and are supplied to digital displays.

Abstract: The control system for electrically operated brakes utilizes solid state electronic components to control the braking mechanism in a towed vehicle. Energy is provided by a pulsating voltage, the pulse width of which is varied by a pulse width modulator in accordance with the amount of braking effort desired for the vehicle being towed. The pulse width modulator has the width of its output pulse directly controlled by either a hand control, or by a foot pedal control, or in response to the brake hydraulic pressure for the hydraulic brake system of the towing vehicle. Protection against short circuit conditions in the towed vehicle is provided which disables the modulator from producing output pulses for a predetermined period of time. Adjustment of the ratio of braking effort in the towed vehicle to the braking effort in the towing vehicle is provided so as to compensate for different towed vehicle to towing vehicle weight ratios.