Abstract: Disclosed is a plug-in base for compact low-voltage protective circuit breakers. The plug-in base comprises a mounting plate and two identical plug-in units disposed thereon at opposite ends thereof. Jumper-like contact laminations are disposed in the plug-in units extending parallel to the current path in a mounted protective circuit breaker. The mounting plate has disposed in the area between the plug-in units a cut-out and a strip extending adjacent thereto which are freely accessible. A padlock may be secured through the cut-out to the strip to prevent mounting of a circuit breaker. The mounting plate is further provided with an extension projecting laterally therefrom which cooperates with a safety tripping pin of a circuit breaker. To lengthen the leakage path and to shield the contacts, the plug-in units have projections and ribs which are placed in front of the contact surfaces of the contact laminations facing a mounted circuit breaker.

Abstract: Disclosed is a power drive for electric switchgear in which the driving force is elastically transmitted to an actuating member, for example, a handle. Thereby, tolerance compensation is provided to allow the drive motor to run into the end positions of the drive. A bending-type spring is disclosed as an elastic power transmitting member which is arranged transversely to the direction of motion of a slide which transmits the driving force to the switchgear. The bending-type spring can be connected to the slide. The bending-type spring can be a leaf spring, and more particularly two parallel leaf springs. In the disclosed embodiments, the two parallel leaf springs are provided as a single U-shaped leaf spring having parallel legs. The U-shaped leaf spring can either be supported at both ends thereof in the slide or the legs can be fastened in a mounting body connected to the slide.

Abstract: A low-voltage circuit breaker has a locking lever to prevent transfer of the circuit breaker handle entirely into its "off" position if the movable contact is blocked in its "on" position by being welded to the fixed contact. The locking lever is rotatably mounted on the control shaft, which is pivotally moved by a drive lever which is connected to the control shaft by a toggle lever system including two toggle levers and a toggle hinge pin joining them together. The fork arms embrace a working surface on the drive lever and the toggle hinge pin. The working surface and the hinge pin are spaced closer together than the arms when the circuit breaker handle is in its "on" position to allow only partial movement of the handle toward its "off" position unless the movable contact is free to move to its "off" position before the locking lever pivots to a position in which it engages both the working surface and the toggle hinge pin. The locking lever can be formed as a double lever with a connecting web.

Abstract: A low voltage circuit breaker has a housing of insulating material divided into an upper part and a lower part along a parting gap. The interior of the housing is subdivided by partitions to accommodate the adjacent pole channels of a multiple pole circuit breaker. The partitions of the upper part and the lower part overlap along their entire length and the outside walls of both housing parts overlap essentially over their entire length having only short interruptions. The overlap of the outer walls and the partitions lengthen the electrical leakage paths within the housing and between adjacent insulating housing and prevent the passage of switching gases into adjacent breaker spaces and between adjacent breakers.

Abstract: In a locking arrangement of an electric circuit breaker which includes a latch and a locking strap which cooperates with the latter and is supported by means of two pivots in support openings of stationary parts, the pivots having a rectangular cross-section and arranged so that the force exerted by the latch on the locking strap is transmitted to one of the small surfaces of the pivots, the support openings have a convex surface which cooperates with the one small surface of the pivot and the long surfaces of the pivots are opposite similarly convex surfaces of the support openings. For the other small surface of the pivots, a concave surface or a surface which consists of two subsurfaces which are at an angle to each other and are connected by a transition arc is provided. The pivots cooperate with the support openings by rolling and sliding motions which insure low stress on the contact surfaces.

Abstract: A low voltage circuit breaker has an insulating housing which is split along a parting line into an upper part and a lower part. Disposed in the housing is an electromagnetic tripping device which comprises a fixed magnet yoke and a movably disposed armature. By means of trunnion (pivot) pins of rectangular cross-section the armature is mounted in bearing openings designed in the form of pocket-like cutouts in the wall surfaces of the lower part which limit the pole channels of the circuit breaker. The bearing surface of the bearing openings associated with a narrow surface of each trunnion pin may be composed of two subsurfaces disposed at an angle to each other so that an edge-like bearing results. For the attachment of the magnet yoke there is provided on the lower part of the housing an island-like projection which is spaced from the wall surfaces and against which the central part of the magnet yoke is caused to rest by a spring element.

Abstract: An actuating device for attachment to a toggle actuated low-voltage circuit breaker having an insulating housing has a housing and a guide mechanism supported therein including a fork-shaped lever which can be turned and which transforms the rotary motion into the rectilinear motion needed to actuating the toggle lever. A slider, movably guided radial to the axis of rotation by the fork arms of the lever, has a circular cylindrical opening which receives a substantially spherical head piece. The head piece contains an opening for receiving the end of the toggle lever. The housing of the actuating device contains a slideway which serves as a guide surface for the head piece. An operating handle can be placed on a shaft end of the fork-shaped lever.

Abstract: A setting mechanism for tripping devices of electrical switchgear has a driven inner member carrying a radially extending, resilient detent arm which interacts with stationary detent slots. For joining with an outer driving member, an interrupted ring snap-in connection is provided between the inner and outer elements which is designed so that eccentric forces as well as asymmetrical spreading forces caused by the resilient detent arm and by the application of torque can be transmitted. For this purpose, two larger posts lying one behind the other on the longitudinal axis of the detent arm have right-angled undercuts and two smaller posts disposed between the first posts are provided with radial projections. The projections have side walls lying in planes extending parallel to the longitudinal axis of the setting mechanism. The setting mechanism members are made as complete parts by injection molding of plastic material.

Abstract: A low voltage circuit breaker having a housing of insulating material separated into an upper part and a lower part. A slot is provided one side wall of the lower part beginning at the parting line and extending to the lower edge of the lower part in which wires leading to an auxiliary device can be installed. An outlet is provided at the separation for these wires. The slot makes it possible to arrange several identical low voltage circuit breakers with connected auxiliary wires directly next to each other.