Abstract: An infusion pump for delivery of drugs to a patient includes a unit in which the pump mechanism is situated and a cassette through which the drugs to be delivered to the patient are pumped. The cassette includes a path for the fluid to flow from a drug vial to an outlet port. Disposed along the path are recesses for an inlet valve, a pressurization region, and an outlet valve. The cassette is sealed by an elastomeric layer to maintain the drugs to be delivered in a contaminant-free condition. The pump includes an inlet valve which has a contour matching the recess of the inlet port, and an outlet valve matching the recess of the outlet port. By biasing the inlet and outlet valves against the recesses, a pumping chamber is created. A piston in the unit pressurizes the pumping chamber to open the outlet valve and permit fluid to escape. By appropriate timing of the operation of the inlet valve and the piston, a continuous stream of fluid is delivered by the pump to the patient.

Abstract: A single-phase ground enclosed load break switch for distribution voltages has a hermetically sealed cylindrical metal housing of from 2 to 6 inches diameter which contains an insulating gas under pressure. The switch has a movable contact assembly to contact a pair of opposed stationary coaxial conductors within the housing. Movement of the contact assembly along one conductor breaks the connection with the other conductor and simultaneously reduces the sliding contact force on the first conductor. The switch has conductive bands coaxially positioned near the housing around the conductors for low voltage measurements monitoring conductor energization and contact position. A rocking bellows at the fulcrum of a crank actuator provides a compact hermetic seal for the actuator without excessive strain of the bellows. A safety interlock with a visual indicator locks the contact assembly in case of a loss of pressure.

Abstract: A single-phase ground enclosed load break switch for distribution voltages has a hermetically sealed cylindrical metal housing of from 2 to 6 inches diameter which contains an insulating gas under pressure. The switch has a movable contact assembly to contact a pair of opposed stationary coaxial conductors within the housing. A rocking bellows at the fulcrum of a crank actuator provides a compact hermetic seal for the actuator without excessive strain of the bellows. A safety interlock with a visual indicator locks the contact assembly in case of a loss of pressure. Excessive pressure in the switch causes the bellows to be punctured with consequent locking of the contact assembly. The switch is small enough to be mounted directly on a transformer or placed into a cable, without the need for a separate enclosure.

Abstract: A vacuum circuit breaker having a movable contact coupled through a wipe cage to an operating member which imparts movement during opening and closing strokes to the movable contact is provided with a latch for latching the wipe cage into its fully extended position during selected portions of the opening and closing strokes.

Abstract: This circuit breaker comprises a plurality of a vacuum-type circuit interrupters, each having a movable contact rod. A common operating device for the interrupters comprises a linearly-movable operating member. The interrupters are mounted at one side of the operating member with their movable contact rods extending in a direction generally toward the operating member. Means is provided for mechanically coupling the operating member to the contact rods, and this means comprises a plurality of insulating operating rods, each connected at one end to the operating member and at its opposite end to one of the movable contact rods. The operating rods are of substantially equal length and have longitudinal axes that converge and intersect at substantially a common point.

Abstract: A vacuum-type circuit breaker comprises (a) a plurality of vacuum circuit interrupters, (b) a common operating member through which closing force is applied to the movable contact rods of all the interrupters, (c) a wipe mechanism for each interrupter, and (d) a plurality of linkages, one for each interrupter, each being connected between the common operating member and the wipe mechanism for the associated interrupter. Each linkage comprises a plurality of pin joints connected mechanically in series between said common operating member and the associated wipe mechanism.

Abstract: A high current interrupter is enclosed in a sealed enclosure having a pair of axially disposed contacts therein, one stationary and one movable relative thereto. An array of rods or electrodes is mounted near each end of the enclosure, the rods extending toward the opposite end of the enclosure and terminating at a free end short of the opposite end. The arrays are similar in pattern and thus each rod lies between and is spaced from rods extending from the opposite enclosure end. Each array of rods is mounted in a pair of thin spaced mounting plates, which are connected together near the centers thereof. The plates engage the rods near the end opposite the free end, both plates being electrically conductive and being connected electrically to one of the two electrical contacts within the enclosure.

Abstract: This current limiting device comprises a normally-closed source-side circuit interrupter, a normally-closed load-side circuit interrupter, an electrical conductor connected between the interrupters for connecting the interrupters in series, and a normally-open switch that can be closed to connect the conductor to ground via a low-impedance conductive path located electrically between the interrupters. A switch operator acts to rapidly close the switch in response to a fault on the power circuit extending through the series combination of interrupters, thereby connecting the conductor to ground through the switch. The switch operator closes the switch within 1/4 cycle of power frequency current after fault inception, thereby effecting current-limiting action with respect to current through the series combination of interrupters on the load side of the conductive path to ground.

Abstract: An electric circuit breaker includes means for providing a predetermined delay between the initiation of a command pulse and the mechanical operation of an element of the circuit breaker in response to the command pulse. In one embodiment, the predetermined delay is provided between a tripping command pulse and the mechanical operation of the trip mechanism of a vacuum circuit breaker. In this embodiment, a translatable armature is coupled to the trip mechanism through mechanical linkage including a flywheel rotatably mounted on a shaft. The shaft is mechanically coupled to the trip mechanism wherein rotation of the shaft operates the trip mechanism. The translatable armature is mechanically coupled to the flywheel so that movement thereof causes the flywheel to rotate through a predetermined rotation. The flywheel includes impact imposing means extending outwardly from a major face thereof. The shaft includes impact receiving means extending radially therefrom.

Abstract: This operating system comprises a fluid motor having a piston, a breaker-opening space at one side of the piston, and a breaker-closing space at its opposite side. An accumulator freely communicates with the breaker-opening space for supplying pressurized fluid thereto during a circuit-breaker opening operation. A normally-closed valve located on the breaker-closing-side of the piston is openable to release liquid from the breaker-closing space so that pressurized liquid in the breaker-opening space can drive the piston in an opening direction. Means is provided for restoring the valve to its closed position following the circuit-breaker opening operation. An impeded passage affords communication between the accumulator and the breaker-closing space to allow pressurized liquid to flow from the accumulator to the breaker-closing space and develop a pressure therein substantially equal to accumulator pressure when the valve is restored to closed position following breaker-opening.

Abstract: An operating device for an electric circuit breaker includes a closing spring and a rotatable spring-controller mounted for rotation between first and second dead center positions with respect to the spring. The spring is charged by transmitting rotational forces to the spring-controller. One end of a connecting link is pivotally connected to a point on the spring-controller which is eccentric with respect to the center of rotation of the spring-controller. Another end of the connecting link is connected to an operating mechanism of the circuit breaker. Circuit breaker closing is effected by allowing the spring to quickly discharge after a charging operation. Damping means is provided for imposing a damping load on the spring-controller substantially only after it has performed its useful work and is undergoing subsequent oscillations. The damping means causes the duration of the oscillations to be substantially reduced so that the spring-controller is rapidly brought to rest.

Abstract: This operating means comprises a circuit-breaker closing spring, a rotatable spring-controller mounted for rotation between first and second dead-center positions with respect to said spring, and means for transmitting charging forces to the spring in response to rotation of the spring-controller in a forward direction from said second toward said first dead-center position. The spring acts to discharge and thereby further rotate said spring-controller in a forward direction when the spring-controller has been rotated in a forward direction past said first dead-center position. Discharge of the spring drives the spring-controller into said second dead-center position, following which the spring-controller oscillates about said second dead-center position to dissipate excess energy then remaining in the parts.

Abstract: An operating device for an electric circuit breaker comprises a closing spring and a rotatable spring-controller mounted for rotation between first and second dead-center positions with respect to the spring. The spring is charged by transmitting rotational forces to the spring-controller through a main pawl mounted on the spring-controller and an abutment on a rotatable driving member. The main pawl is released from driven engagement with the abutment at the end of a spring-charging operation. Normal circuit-breaker closing is effected by allowing the spring to quickly discharge after a charging operation.A manual slow-close operation of the circuit breaker is effected through an auxiliary pawl mounted on the spring-controller in a position angularly-spaced from the main pawl. During normal spring-charging and discharging operations, this auxiliary pawl is prevented from engaging the abutment on the driving member.

Abstract: This hydraulically-actuated operating system comprises a cylinder, a piston movable therein in an opening direction to open a circuit breaker, and an accumulator for supplying pressurized liquid to a piston-actuating space within the cylinder. A normally-closed valve between the accumulator and the actuating space is openable to allow pressurized liquid from the accumulator to flow through the valve into the actuating space to drive the piston in an opening direction. A vent is located hydraulically between the actuating space and the valve for affording communication between said actuating space and a low pressure region.Flow control means is provided for restricting leakage through said vent to a rate that prevents said leakage from substantially detracting from the development of pressure within said actuatng space during the period from initial opening of the valve to the time when said piston has moved through most of its opening stroke.

Abstract: An operating device for an electric circuit breaker comprises a closing spring and a rotatable spring-controller mounted for rotation between first and second dead-center positions with respect to the spring. The spring is charged by transmitting rotational forces to the spring-controller through a pawl mounted on the spring controller and an abutment on a rotatable driving member. Cam means is provided for releasing the pawl from driven engagement with the abutment at the end of a spring-charging operation. Circuit-breaker closing is effected by allowing the spring quickly to discharge after a charging operation.Discharge of the spring carries the spring-controller into said second dead-center position and produces oscillations of the spring-controller immediately following such discharge. The cam means holds the pawl out of a collision path with respect to said abutment during such oscillations, even if such oscillations should carry the spring-controller through as much as 90.degree.

Abstract: This vacuum-type circuit breaker has means for substantially reducing the tendency of the contacts to bounce apart in response to the impact between the contacts occurring at the end of a closing stroke. The circuit breaker includes a contact-wipe mechanism comprising a driving part and a wipe spring located between the driving part and the movable contact which spring is loaded to produce added closing force on the movable contact by continuing closing motion of the driving part after the contacts initially engage at the end of the closing stroke. The wipe mechanism further includes a bounce-suppressing spring acting in opposition to the wipe spring and discharging to aid said continuing closing motion of said driving part during the initial stages of said continuing motion following initial contact-engagement.The wipe mechanism also includes means for precisely controlling the forces imposed on the movable contact by acceleration at the start and termination of a contact-opening stroke.

Abstract: A vacuum-type circuit breaker comprises a conventional wipe mechanism interposed between an operating member and the movable contact of the breaker. The wipe mechanism comprises a driven part coupled to the movable contact, a driving part coupled to the operating member but movable with respect thereto, and preloaded spring means between said driving and driven parts.First stop means is provided for stopping said operating member at the end of its circuit-breaker opening stroke with such abruptness that said driven member, against the opposition of said spring means, overruns the driving member following such stopping. Such overrunning of the driven member is limited by second stop means comprising a stop carried by said operating member.

Abstract: A gas-blast interrupter of the puffer type comprises a piston positively connected to the movable contact rod of the interrupter and means defining a pumping space at one side of the piston containing gas compressed by piston motion during an opening operation. At the opposite side of the piston there is a working space in which compressed gas can act upon the piston to aid an opening operation. A blast passage is provided through which gas from the pumping space can flow into the arcing region. An auxiliary passage affords communication between this blast passage, and said working space.Valve means effective during a low current interruption blocks flow through the auxiliary passage and allows free communication between the pumping space and the blast passage, whereby during a low current interruption, compressed gas from the pumping space can flow into the arcing region via the blast passage.

Abstract: This electric circuit breaker contains electromagnetic-assist means for opposing the contact-repulsion forces developed when a high current flows through the breaker. The assist means comprises a rigid supporting member which can be restrained in a fixed position to render the assist means capable of transmitting closing force to the movable contact of the breaker but which supporting member is releasable to render said assist means generally ineffective to transmit closing force to said movable contact. The assist means further comprises a toggle connected between the supporting member and the movable contact for imparting a closing force to the movable contact when forced toward an in-line position while said supporting member is restrained.For forcing the toggle toward its in-line position, there is provided magnetic structure cooperating with a conductor connected in series with the circuit breaker contacts.

Abstract: A liquid-metal circuit protector comprises two liquid-metal current limiting devices electrically connected in parallel with each other. Each current limiting device comprises a pair of spaced terminals and a passageway extending between said terminals and containing liquid metal. The passageways are hydraulically connected in series in a hydraulic circuit loop. Pumping means operated by current through the protector forces liquid metal around the loop via each of the passageways, and heat exchange means external to the passageways cools the liquid metal during its flow through the loop.