摘要:
A high-voltage circuit-breaker has an interrupting chamber comprising a gas-tight cylindrical casing filled with a gas having good insulative properties such as sulfur hexafluoride. The casing contains a fixed permanent contact, a fixed arc contact and a mobile assembly comprising permanent contacts and arc contacts and associated with a gas blast assembly. The chamber also contains a carbon-based resistor having a resistance of approximately 500 ohms connected in parallel with the circuit-breaker contacts when the arc contacts are opened by an auxiliary switch. This resistor is connected in series with an arrangement of varistors, the resulting combination being disposed inside the casing and connected in series with the auxiliary switch. Opening of the auxiliary switch is effected by opening of the circuit-breaker. The volume of the resistor is greater than that of the arrangement of varistors by a factor of at least five.
摘要:
A high tension circuit breaker includes a gastight cylindrical insulating case filled with SF.sub.6 gas or the like and defining for each phase at least one current interrupting chamber. A fixed main contact and a fixed arcing contact are fixedly mounted within the chamber. Moving equipment of the circuit breaker includes moving main and arcing contacts and a member for moving the moving main and arcing contacts towards and away from the fixed main contact and the fixed arcing contact. A cylinder is fixedly mounted in said chamber and supports internally a movable blast piston and terminates in a blast nozzle facing the fixed contacts. A capacitor is disposed inside the circuit interrupting chamber optionally with a parallel connected varistor. A mechanism in the form of a switch including a fixed and a movable contact operates to insert the capacitor and the parallel connected varistor temporarily during both closing and opening of the circuit breaker contacts. The capacitor is constituted by a stack of capacitor components disposed in a fixed insulating tube mounted within the chamber. A first end of the stack is electrically connected to a first current terminal of the circuit breaker, and a second end of the stack is electrically connected to an electrode fixed to a piece of the moving equipment and electrically connected to a second current terminal of the circuit breaker. The electrode may be a tube coaxial with the case and internally of the case.
摘要:
A surge limiting circuit breaker has, for each phase, at least one interrupting chamber constituted by a gastight insulating enclosure filled with a gas having high dielectric strength. The enclosure contains fixed and moving main contacts and fixed and moving arcing contacts. Moving equipment effects movement of the moving contacts relative to the fixed contacts. The enclosure includes a varistor. The varistor is inserted in parallel with the circuit breaker contacts on separation of the main contacts when the circuit breaker is being opened, disconnecting the varistor before the end of the stroke of the moving arcing contact. The varistor is inserted in parallel with the circuit breaker contacts while closing the circuit breaker and prior to bringing the arcing contacts into contact with each other. The varistor is short-circuited when the arcing contacts come into contact.
摘要:
A safety device for an electrical apparatus comprising an enclosure filled with gas under pressure, the safety device comprising first means for detecting the appearance of an arc inside the enclosure, and second means controlled by the first means to establish a path for the gas through the enclosure when the first means has detected an arc for a given length of time.
摘要:
An automated lawn mower has a frame that is attached to a conventional lawn mower to retrofit the conventional lawn mower for automated lawn cutting operations. In some embodiments, one or more wheels of the conventional lawn mower are removed, and the frame is coupled to the lawn mower at one or more connection points for the removed wheels. The frame is coupled to a motor, a controller, and a plurality of wheels. During operation, the motor drives the wheels under the control of the controller in order to move the automated lawn mower over a lawn for grass cutting operations.
摘要:
An unmanned aerial vehicle delivery system utilizes an unmanned aerial vehicle (UAV) to deliver packages between an initiation point and multiple delivery points at a raised elevation. The UAV flies between points in an organized manner, using logistical, maintenance and safety software, commands from a delivery organization, and guidance tools to coordinate deliveries. One advantage of the system is that the UAV engages the delivery points at a raised elevation, rather than the ground level. The UAV docks through an elevated structure at the delivery point for delivering the package and replenishing a power source. The package is conveyed from a docking end and through a central shaft of the elevated structure by means of an elevator. The package then travels to a lower structure, such as a house or office, for pickup. After completion of the delivery, the UAV replenishes its power source and/or continues on the delivery route.
摘要:
Process for manufacturing of an optical article which comprises: making available an organic substrate based on an organic polymer having a degree of water uptake of greater than or equal to 0.6% by weight, with respect to the total weight of the substrate, the degree of water uptake being equal to the weight of water absorbed by the material after drying and then storing for 800 hours in a chamber at 50° C. under a relative humidity of 100% and at atmospheric pressure; forming a hard abrasion-resistant coating on the substrate by heating the substrate at a temperature of greater than or equal to 90° C. for a period of time of at least 20 minutes; exposing the substrate covered with the hard abrasion-resistant coating to a humid atmosphere, so as to restore, to the organic substrate, the water evaporated during stage; and depositing of a water-impermeable inorganic coating by vacuum evaporation.
摘要:
One embodiment of a lighting system may have a rotating unit that may include a body movable in a plurality of rotational patterns and a motor that may be configured to move the body in the plurality of rotational patterns. The lighting system may also have a light source that may be carried by the body. The light source may have a light emitting section that may be configured to emit light. In addition, the lighting system may further include a light scattering device that may be carried by the light emitting section of the light source. The light scattering device may be configured to scatter the light emitted from the light source for producing a plurality of illumination patterns that may be based on the plurality of rotational patterns of the body.
摘要:
A circuit-breaker having two interrupting chambers per pole, the chambers being disposed in a T or V configuration at the end of a column provided at its base with a control system for operating a drive rod, each chamber containing a moving assembly connected via a linkage to the drive rod, and main contacts and arcing contacts, wherein each chamber contains a semi-moving assembly including main contacts and arcing contacts co-operating respectively with the main contacts and the arcing contacts of the moving assembly, the semi-moving assembly in each of the chambers including a mechanism for moving it at a velocity of equal magnitude and of opposite direction to the velocity of the moving assembly with which it co-operates.
摘要:
The pins which are used for the support of a core in a lost wax casing process are provided with caps. The caps provide sufficient surface area for encapsulation by ceramic slurry. Heat loss from the metal melt via the pins is thus obviated along with undesirable grain nucleation.