I-t-e Imperial Corporation

Carl E Gryctko

Kenneth D Ball

Peter J McGinnis

Charles T Robins

Anthony B Michetti

In certain applications, such as solderless cable connectors, a set screw is used to provide the connection between two or more current conductors. The set screw should be tightened to no more than a predetermined tightening torque. This is automatically accomplished by providing a section along the length of the set screw that is weakened to a predetermined extent, which causes the screw to break at the section upon attainment of the predetermined tightening torque. Both portions of the separated screw include means for being engaged for tightening or loosening the screw.

Torque controlling set screw for use with the cable of solderless

A unitized combination motor starter includes a unitized insulating base for an electromagnetic contactor section and a circuit breaker section having automatic trip means. The unitized base is part of a common insulating housing for the contactor and circuit breaker sections and circuit elements serially connecting these sections are disposed within the common housing.

Unitized combination starter

A molded case multi-pole circuit breaker is provided with a solid state trip unit constructed to automatically open the breaker responsive to predetermined fault current conditions by actuating a permanent magnet latch. The latch and main conductors of the circuit breaker are constructed and arranged so that at very high short circuit currents, even if the solid state circuitry malfunctions, flux generated directly by current flow in the main conductors will buck the permanent magnet flux sufficiently to actuate the magnetic latch directly.

Direct fault tripping of circuit breaker having solid state trip means

A molded case multi-pole circuit breaker is provided with a solid state trip unit constructed to automatically open the breaker responsive to predetermined fault current conditions by actuating a permanent magnet latch. The circuit breaker is also provided with a thermal-magnetic trip means that acts independently of the solid state trip unit to automatically open the breaker responsive to predetermined fault current conditions.

Circuit breaker having solid state and thermal-magnetic trip means

An electric motor for driving a circuit breaker operating handle is connected to the latter by two sets of linkages. The first set of linkages includes a drive arm and a driven arm mounted on fixed spaced centers and interconnected by a cam means. The drive arm is pivoted by connection to the drive motor through gearing and a slip clutch, and mounts a roller entered into a cam slot formed in the driven arm. The second set of linkages consists of a drive link and a main link also mounted on fixed spaced centers with the main link having means for engaging and moving a circuit breaker operating handle. The drive and main links are connected by a roller-slot arrangement, with the roller being positively guided along an arcuate path formed about a center remote from the centers of the links and arms. Positive guidance of this connecting roller causes the effective lengths of the links to change in accordance with different positions of the circuit breaker handle. The centers of the driven arm and drive link coincide so that movement of the driven arm causes corresponding movement of the drive link. The combination of cam connected drive and driven arms together with a positively guided roller to change the effective lengths of drive and main links enables a relatively small electric motor to rapidly operate a very large circuit breaker.

Electrical operator for circuit breakers

A removable and replaceable solid state trip unit assembly for automatically opening a molded case multi-pole circuit breaker, is constructed so as to be interchangeable with a thermal-magnetic trip unit assembly.

Interchangeable solid state and thermal-magnetic trip units

A molded case multi-pole circuit breaker is provided with a solid state trip unit constructed to automatically open the breaker responsive to predetermined fault current conditions. In addition, a bimetal actuated device sensitive to air temperature within the breaker housing is provided for automatically opening the breaker when air temperature within the housing exceeds a predetermined level.

Circuit breaker having thermal and solid state trip means

A molded case circuit breaker having a spaced plate arc chute for each pole thereof, with each arc chute having a V-shaped mouth region at one end and having separable arcing contacts positioned at the mouth region and having a space defined opposite the mouth region and between a cover plate region and a terminal bus for obtaining access to terminal mounting bolts, is provided with at least one arc chute extension attached to a cover panel portion. Each arc chute extension consists of a plurality of spaced conductive plates and insulated means for rigidly positioning each of the plates in close planar alignment with a plate of the arc chute to present an increased length serpentine path for extinguishing an arc produced by the interruption of voltages and currents in excess of the original arc chute rating. Arc chute extensions are introduced as a single unit to increase the interruption rating of as many poles of the circuit breaker as is required.

Arc chute extension for increased interruption rating

An electrical connector is constructed by inserting the end of a stranded cable into a loosely fitted sleeve having diametrically opposed apertures. Thereafter, the sleeve is crimped for securement thereof to the cable. The crimping tool is provided with a punch section that moves through the sleeve apertures and in so doing pierces the cable by spreading the strands thereof, thereby forming a through passage for insertion of a mounting bolt that will be received by a threaded aperture in a terminal. During the crimping operation the sleeve is formed with an extensive flat surface area that will be in intimate contact with the terminal.

Method of forming a crimp-type electrical connector

A rotary handle operator mechanism is fixedly mounted in an enclosure having a circuit interrupter mounted therein on the rear wall thereof. The mechanism includes a main handle disposed outside the enclosure for manual operation and being keyed to a cam unit engaged with the circuit breaker handle. A latch unit, including a cover latch section, is provided with a notch formation and a cam formation that cooperate with a forwardly extending pin of the cam unit to provide a switch interlock and a cover latch release.

Circuit breaker operator with defeates interlock mechanism

A rotary handle mechanism for operating a switch device secured to the rear wall of an enclosure is mounted separate from the enclosure cover and extends through a cover opening to be operable from outside of the enclosure when the cover is closed. The mechanism is designed so that the elements thereof may be assembled selectively for operation within an enclosure having a cover that is hinged along one or the other of its edges.

Circuit interrupter having rotary switch operator and interlocking

A circuit breaker module and a detector module are mounted side by side to form a ground fault interrupter. The detector module includes an electromagnet for mechanical engagement with operation of the automatic trip device of the circuit breaker to open the latter upon the occurrence of predetermined ground fault conditions. An indicator member is pivotally mounted between the detector and circuit breaker modules. When the electromagnet is energized, it moves the indicator member from a retracted to an indicating position. In the latter position a portion of the indicator member is readily visible to indicate that tripping has resulted from a ground fault rather than from an overload.

Ground fault circuit breaker with ground fault trip indicator

A fused GFI unit for manually controlling the application of electrical power to a utilization device while automatically protecting the device and personnel associated therewith from electrical hazards, includes a switch plate unit have an insulated handle for controlling mechanical current interrupting means. Fuse receptacle means is provided in series connection with the switch pole to protect the GFI unit and the power lines against overcurrent hazards. A ground fault detector operates an actuating member in mechanical cooperation with the latched portion of the switch mechanism to enable current interruption by the switch pole in the event an unbalanced current flow is produced in one of a pair of power lines by a personnel hazard. A compact sectionalized structure encasing the switch, the fuse receptacle means and the GFI detector results.

Fused GFI unit

A circuit protective arrangement which utilizes a circuit breaker, current limiting fuse and ground fault interruption means in a closely coordinated operation to achieve reliable current interruption in the event that an overcurrent or ground fault hazard occurs. The source voltage is above the voltage rating of both the circuit breaker and current limiting fuse devices and the available current from the source is in excess of the rated current interruption rating of the circuit breaker. A compact sectionalized or modular structure for replacement of an existing circuit breaker is shown.

Growing community of inventors

Haddon Heights, NJ, United States of America

Carl E Gryctko