Abstract: Disclosed is an improved switch structure having forcedly opening-and-locking mechanism installed therein. It is responsive to the sticking of the movable and stationary contact elements for forcedly breaking an associated heavy-current carrying circuit which otherwise, would remain closed through the stuck contact elements. The forcedly opening-and-locking mechanism comprises an auxiliary contact section spring-biased to retain the stationary contact element in conductive condition to the associated circuit. It is responsive to the sticking-and-rising of the movable and stationary contact elements for allowing the stationary contact element to be apart from the conductive position to the associated circuit by yielding the rising force of the stuck contact elements until the locking position is reached, in which position the stationary contact element is kept in non-conductive position.

Abstract: A safety switch with a contactor structure including first and second contactor contacts electrically connected to each other. The switch has an "on" state in which first and second terminal contacts are contacted with the first and second contactor contacts, respectively, to thereby electrically connect the terminal contacts therebetween, and an "off" state in which the terminal contacts are not electrically connected to each other by the contactor structure, whereby current cannot flow between the terminal contacts. The switch also has a cycle control mechanism with a normal-state in which the switch is free to cycle between the "on" and "off" states, and a welded-state in which one of the terminal contacts is welded to one of the contactor contacts and the other of the contactor contacts is separated from the other of the terminal contacts. When the cycle control mechanism is in the welded state, the switch is prevented from moving from the "off" state to the "on" state.

Abstract: An electrical contact assembly of the present invention includes a body having a housing and a cover defining a space. A pair of spaced terminals are received in the space. One of the terminals has a contact formed at a free end thereof. The other contact has a spring arm secured to its free end. A contact is mounted on the spring arm in a position in which it can be moved into contact with the first contact. An extension is provided on the spring arm and a stop is provided in the body. When contact operation causes or attempts to cause tack welding of the two contacts, the stop extension operation maintains a spring force on the spring arm sufficiently strong to break the tack weld so that the contacts can be opened.

Abstract: A circuit breaker with a blocking mechanism having reversing levers which are rotatably mounted on both sides of the supporting lever of the circuit breaker, which reversing levers are in contact with the upper toggle in an interlocking manner. The reversing levers are moved when the switch latch moves. If there is an attempt to switch "off" when the contacts are welded together, the further movement of the switch latch is prevented by stops on the selector shaft. When switching "off" is performed when the contacts are satisfactorily open, the reversing levers automatically reverse the toggle system with regard to overcoming the throw-over point thereof, so that the "off" position of the circuit breaker is reached reliably.

Abstract: A device for separating a pair of electric contacts which tend to weld and consist of a stationary contact 11 and a contact 12 which is movable away from the stationary contact, particularly in a circuit breaker is provided. The device includes a tripping lever 17, which is biased in a contact-separating direction and serves to actuate the movable contact 12, and means 19 for holding the tripping lever 17 in its stand-by position. The movement of the tripping lever 17 from its stand-by position involves a displacement of a lever fulcrum to a first position where a strong separating force is exerted on the movable contact 12 and then to a second position where a weaker separating force is exerted on the movable contact 12.

Abstract: A microswitch comprising a housing, a switching tappet, connection contacts connected with fixed contacts positioned in the interior of said housing, and a contact bridge with at least one switching contact movable from a first to a second switching position by way of the switching tappet. The contact bridge is held in its first or second switching position by means of a bistable spring arrangement. The microswitch has structurally simple forced, separation means without any necessity for change in the overall size. Its switching tappet is provided with a cantilever with a holding-down device at one end which, in the first switching position of the contact bridge is arranged at a small distance from said contact bridge and which, in the second switching position, projects into the path along which the contact bridge moves.

Abstract: An operating mechanism of a multipole circuit breaker comprises a toggle associated with an automatic tripping hook and an operating handle cooperating with a pivoting locking lever arranged to block the handle in an intermediate position in case of welding of the contacts. When normal opening of the contacts takes place, the locking lever comprises a radiating bearing surface cooperating with a protuberance of the bar to keep holding the locking lever in the first active position of the stop, during a first part of the opening travel of the movable contact of each pole, and a notch for receiving said protuberance causing unblocking of the locking lever to release the base close to the end of opening travel of the movable contact.

Abstract: A molded case circuit breaker includes an interlock which prevents the operating handle from being moved from the on position after the main contacts have been welded together. By preventing the operating handle from being moved from the on position during such a condition, the operating handle will indicate the correct status of the main contacts and the operator will be made aware that the main contacts are welded together.

Abstract: A plunger operated switch has a pair of movable contacts on a movable contact carrier bridged by a secondary contact supported on a pushbutton operator member which is biased apart from the contact carrier. Depression of the pushbutton operator for the plunger assembly moves the primary movable contacts into bridging engagement with the stationary contacts through the secondary contact member. In the event the primary movable contacts weld to the stationary contacts and an operating force is removed from the plunger operator, a spring biases the secondary contact away from the primary movable contacts to open the bridging relationship therebetween and open the circuit controlled by the switch. A pair of normally closed contacts are arranged for operation by the pushbutton operator so that the contacts open before the main contacts close and close after the main contacts open, rendering them particularly suitable for use as dynamic braking contacts in a motor control application.

Abstract: A positive off mechanism for a circuit breaker includes a pair of positive off levers slideable in slots in the side plates and extendable into the path of the operating handle to prevent movement of the handle to the off position when the contacts are welded closed. The positive off levers are actuated by positive off links pivotally mounted to the side plates and coupled to the positive off levers by "dog bone" connections. The positive off links in turn are actuated by the toggle mechanism of the circuit breaker which collapses to open the contacts during normal circuit breaker operation, but which remains erect when the contacts are welded closed.

Abstract: A pair of lock links straddling and pivoted on the same pin as the latchable cradle of a circuit breaker follow the toggle device of the breaker either by riding on the toggle knee pin or through a pin which bears against the edges of the toggle arms. The lock links have extensions which engage the handle yoke to prevent the handle from being moved to the off position when the circuit breaker contacts are welded closed causing the toggle device to remain erected.

Abstract: Elastic devices (3) abruptly actuate a contact carrier (9) in the upward direction when a push-member (1) reaches a tensioning position (E) from a position of rest (R). In the event of any blockage preventing such abrupt movement a lever (24) constrainedly produces the movement when the push-member (1) continues its movement as far as a constrained actuation position (A). The push-member carries colored zones (101, 102). The contact carrier carries a colored zone (104). From the relative position of these zones viewed through a window in the casing (100), the user can adjust the positioning of the limit switch with respect to a movable member intended to actuate it so that the two phases of the actuation take place at the required points. The user can also check whether the contact carrier moves in response to the elastic devices or in response to the lever.

Abstract: A pair of lock links straddling and pivoted on the same pin as the latchable cradle of a circuit breaker follow the toggle device of the breaker either by riding on the toggle knee pin or through a pin which bears against the edges of the toggle arms. The lock links have extensions which engage the handle yoke to prevent the handle from being moved to the off position when the circuit breaker contacts are welded closed causing the toggle device to remain erected.

Abstract: Apparatus is provided for an electrical circuit breaker for preventing the handle thereof from being moved to the OFF position when the electrical contacts of the circuit breaker are welded closed. This apparatus mechanically limits the travel of the operating handle so that it may not be moved to the OFF position when the electrical contacts are closed. This restrictor apparatus as it is called is mechanically connected to, but out of direct contact with the handle arm of the circuit breaker. The mechanical linkage between the operating handle and the contact arm of the circuit breaker includes a projection. During the foregoing condition, the projection will interact with a crossbar assembly for the contact arm of the circuit breaker.

Abstract: The handle of a circuit breaker is blocked from movement to the off positiion, when the contacts are welded closed, thereby preventing rotation of the common cross-bar on which contact arms carrying the movable contacts are mounted, by an interlock which includes radial extensions on the arms of a pivoted handle yoke which radially engage projections on the cross-bar.

Abstract: A circuit breaker includes an interlock which prevents movement of the handle to the off position when the contacts are welded closed. The interlock includes a pair of floating links which jam between slots in arms of the yoke of a spring powered operating mechanism which carries the handle, and recesses in the rotatable cross-bar carrying the movable contact arms. The recesses are offset from the rotational axis of cross-bar so that an attempt to move the switch to the off position generates a moment which will break open lightly welded contacts.

Abstract: A molded case circuit breaker includes an interlock which prevents the operating handle from being placed in the off position after the main contacts have been welded together. By preventing the operating handle from being placed in an off position during such a condition, the operating handle will indicate the correct status of the main contacts and the operator will be made aware that the main contacts are welded together.

Abstract: A split switch case has a base and a mounting bracket fitted thereto. The top wall of the latter has a lateral rib defining sockets for receiving shoulder portions of the actuator. Plungers in the actuator can bottom out to break free the switch contacts should they fuse together. The rocker has a unique shape and is coupled to the actuator for positive pivotal movement on a lateral axis defined by surfaces in the rocker and in the mounting bracket's top wall rib. In the illuminated switch shown, the lamp circuit has at least one lead provided in a slot defined inside the mounting bracket. The lamp can be mounted in the mounting bracket either from above or from below, two depending legs will accommodate a conventional LED from either direction.

Abstract: Apparatus which is mechanically connected to and out of direct contact of the handle arm of an electrical circuit breaker to prevent the operating lever of the circuit breaker from being moved to the off position when the contacts of the circuit breaker are closed, due to a weldment of the contacts or obstruction of the contact arm carriers. In particular, a two part toggle mechanism is provided for opening and closing contacts in conjuction with the movement of the operating lever. The lower toggle link has a protrusion thereon which abuts against the rotatable crossbar mechanism which carries the contact arm of the moveable contacts if the contacts have not separated as the operating lever is moved from the closed to open position. The abutments, however, will rotate free of the crossbar if the contact arm moves in conjunction with the movement of the crossbar as the lever is moved from the open to closed position.

Abstract: A circuit breaker having positive contact indication. Upon the circuit breaker tripping, the operating mechanism components unlatch, moving the cradle, upper link and lower link upwards and opening the contacts. Upon the circuit breaker being manually opened, no operating mechanism components move except the upper link and lower link which causes the contacts to open. Upon the occurrence of locked contacts and the operating mechanism receiving a trip signal, the operating mechanism components unlatch but move only slightly since the contacts cannot open. A shuttle, pivotally mounted on the cradle, moves upward slightly to catch its tail on a flipper spring. The shuttle rotates slightly to meet a tab positioned on the handle arm and to block and opening movement of the operating handle.

Abstract: An electrical switch construction and method of making the same are provided, the switch construction having a support carrying a pair of spaced apart first and second fixed contacts and a movable switch blade unit carrying a contact unit for being disposed in contact with the first fixed contact and out of contact with the second fixed contact when the switch blade unit is in a first position thereof and for being disposed in contact with the second fixed contact and out of contact with the first fixed contact when the switch blade unit is in a second position thereof.

Abstract: A miniature switch which has reduced susceptibility to welding of contact elements due to high voltage arcing. The switch has parallel resilient spring like current carrying members each having a contact portion mounted adjacent an end thereof. A selectively actuatable switch plunger is adapted to bend the free end of one of the contact members about its fixed support so that the contact portion thereof contacts the contact portion of the other current carrying member, which in turn bends about its fixed support. Upon removal of the operating force of the plunger, the current carrying members spring back to their normal horizontal positions, breaking the electrical contact between the contact portions. The making and breaking actions are made in a slow manner so that the possibility of bouncing between contact elements and the consequent welding due to high voltage arcing, is greatly reduced.

Abstract: A safety switch for automatically interrupting a circuit when its main contacts are fused or stuck together in the "ON" position comprises a housing containing a pair of main contacts and auxiliary safety contacts which are normally closed but are automatically opened when the main contacts fuse together. One main contact is an "ON" contact, and the other main contact is carried by a movable switch arm. A first spring in the housing mechanically coupled to the movable switch arm normally urges the movable main contact into open position away from the engagement with the ON contact. Switch operating means include a movable actuator to overcome the biasing force of the spring for moving the movable main contact to closed position into engagement with the ON main contact for energizing a circuit controlled by the main contacts.

Abstract: A switch for providing a safety function when its main contacts are fused or stuck together in the "ON" position, comprising a housing containing a pair of main contacts, one being designated an ON contact, and the other main contact being carried by a movable switch arm in the housing. This switch arm has a first end which carries the movable main contact and a second end, and spring means mechanically coupled to the movable switch arm normally bias the movable main contact toward open position away from engagement with the ON contact. Switch operating means including movable actuator means overcome the biasing force of the spring means for moving the movable main contact to closed position into engagement with the ON main contact.

Abstract: A reciprocable push button achieves sequential switching (ON/OFF or ON/ON) through a simple coil spring and pivoted contact lever. The push button has depending legs that cooperate with camming means inside the switch case to swing the contact lever from side-to-side as it pivots between its limit positions. This compound contact lever action is achieved with the push button's straight line motion to provide this sequential switching function.

Abstract: The electrical switch which may be of a type having a toggle mechanism or a buckling mechanism for achieving abrupt motion of its movable piece. The switch is additionally provided with a mechanism for forcibly disengaging a movable contact formed on the movable piece away from a fixed contact even when the movable contact and the fixed contact are welded together due to heat generated from the contacts. This mechanism may conveniently include a pair of rack gears and a pinion gear so that the force applied to the switch is also transmitted to the disengagement mechanism for, in addition to normal switching action, pulling the movable contact away from the fixed contact.

Abstract: To be able to disengage the contacts of a switch in the event of a breakage of the snap spring or if the contacts become melted together, a pivotable resetting member in the form of a two-armed lever is provided. One arm of the lever is associated with the inside end of an operating plunger, while its other arm is associated with the end of a slide of the switch. While being displaced from its initial position into the switched position, the slide pushes the resetting member and the end of the operating plunger moved thereby away from the respective arm of the resetting member. By pushing the operating plunger against the actuator, the end of the plunger acts against the arm of the resetting member whose pivotal motion then causes the slide to be pushed into its initial position.

Abstract: A double pole switching device has a plunger which is longitudinally movable in a housing against a spring force and has at least one contact bridge provided with a movable contact switch to operate with immovable contacts, and an element is provided for forcibly opening of adhering or welded contacts and includes a U-shaped bracket with a connecting web located between the contact bridge and a contact pressure spring and two legs cooperating with stepped extensions in the housing so that the bracket and the contact bridge over a first part of the stroke of the plunger are forcibly taken along, and the legs of the bracket over a further part of the stroke are spread outwardly and release the plunger.

Abstract: An electric switch including fixed and movable contacts, the movable contact being carried by a pivoted arm movable between a first position at which the fixed and movable contacts are in closed contacting relationship and a second position at which the fixed and movable contacts are in open noncontacting relationship, a control lever, a pivot mounting the control lever for movement between first and second positions thereof corresponding to the closed and opened positions respectively of the contacts, a toggle linkage including a plurality of links operatively interconnected between the arm and the control lever, a spring connected between the toggle linkage and the control lever for moving the arm from the first position thereof to the second position thereof and vice versa upon movement of the control lever respectively from the first to the second positions thereof and vice versa absent the contacts being welded together in the closed position thereof, the links being disposed generally in-line in the clo

Abstract: An electrical contact device for transmitting heavy currents between relatively rotatable parts, for example between a fixed welding transformer and a rotatable unit which supports a spot welding gun. The contact device comprises a spaced-apart pair of annular, axially fixed, contact segments on one unit and, between these, an axially displaceable pair of annular contact disks on another unit. The disks are urged towards each other by springs and are thereby centered by a centering device to provide a well-defined clearance between each contact disk and the confronting contact segment, and the disks are pressed outwardly against the co-acting contact segments, to eliminate said clearances when current is to flow therebetween, by an annular operating device. The contact device has particular utility in robotics and prevents wear at the contacting surfaces on the appearance of relative rotation therebetween.

Abstract: Two identical toggle springs of a snap action switch are inserted in the same knife-edged bearings and are spaced apart in the region of their clamping locations and are activated by the same plunger. There are two control arms connected to the toggle springs each having a movable contact. The relative distance between the control arms is limited by a lost motion buffer. Stationary contacts are positioned above and below the movable contacts. The control arms are actuated by the plunger and move in the same direction as the plunger establishing contact between one of the movable contacts of the control arms and one of the stationary contacts.

Abstract: A contactor apparatus comprising means for automatically opening power circuits should faults occur and a local control member.This apparatus comprises a plurality of power lines (8) each comprising a power contact (2) adapted to be opened during a short circuit by a striker (28), a coil (13) and a bimetallic strip (14), responding to smaller overloads. The elements responsive to overcurrents act on a cascade of sudden tripping devices (19) (17) (31) which govern the positions of the local control member (18) and act on a control switch (4) placed in series with the electromagnet (1).Such an apparatus is advantageously used in installations where protection of the lines, remote control and local control of the consumer apparatus are desired.

Abstract: A contactor apparatus is provided comprising automatic opening means and a local control member.This apparatus uses a transmission piece (40) associated with a sudden tripping mechanism (46) which is released by a bolt (29) held in position by means of a lever (24) which may be struck by a magnetizable part and adapted to maintain a power contact (13) open, this part assuming, after the appearance of a fault, visible positions so as to inform the user about the state of the apparatus.This apparatus is usable in installations where it is desired to protect the lines and the loads.

Abstract: A switch having a housing and within the housing a control plunger formed with a transverse opening through which a contact arm passes transversely to the direction of movement of the plunger; a tension spring urges the contact bridge against the plunger and the free ends of the bridge cooperate with stationary contacts mounted in the housing; another compression spring urges the plunger into its starting position; the free arms of the contact bridge support, respectively, detaching blocks having arresting edges engageable with the plunger in the event when, during the movement of the plunger, the contact arm accidentally sticks to the stationary contacts; the detaching blocks are provided with abutment surfaces cooperating with guiding edges on the inner wall of the housing to disengage the projection from the plunger.

Abstract: In the low-voltage circuit breaker that has a toggle lever system connecting the actuating arm to a carrier that moves the movable contact, a locking lever is provided to prevent transfer of the operating lever handle to its "off" position if the movable contact is welded to the stationary contact. The locking lever is pivoted about a bearing support formed in the housing of the circuit breaker. The opposite end of the locking lever is connected to the handle to be pivoted by it. The locking lever has an angled-off projection that extends into the path of movement of the carrier and is positioned to engage the carrier if the latter is unable to move from its "on" position due to welding of the contacts together. When the contacts are not welded together, the locking lever enforces the toggle levers to snap through to their "off" position before the angled-off part of the locking lever comes into contact with the carrier of the movable contact.

Abstract: A vacuum-type contactor assembly is provided having an operating linkage such that a fault, or heavy overload currents, will cause a maintenance of the contact-closed position, and a pair of springs are provided in the operating linkage, one of which is purely an atmospheric pressure compensating, or "kickoff", spring, whereas the other is a heavy contact pressure spring compressed following contact closure, and serving to provide both a hammer action at contact separation to break any welds occurring at the contact structure, and an accelerating force during contact opening.Preferably, an electromagnetic actuating mechanism is utilized to effect the short travel and high contact forces typically required by vacuum-type switches.

Abstract: In order to effectively disconnect a contact bridge from fixed terminals, even though the contact bridge may be sticking to the contacts, or may be welded or hang, a plunger-type armature core is slidable within a central sleeve of a solenoid for a travel path which is in excess of the connecting path length of the contact bridge towards the fixed terminals. Upon disconnection, a spring returns the armature plunger and, with it, a switching rod which will pass through the overtravel path length before engaging the contact terminals, if the contact terminals should stick, thus exerting a blow against the connecting bridge and tearing it away from the contact terminals.

Abstract: A snap switch comprises a control button, a control rod slidable with the control button via a spring, two pairs of contacts associated, respectively, with two pairs of terminals, the two contacts of each pair of contacts being connectable by resilient conducting means under the action of a setting spring fixed to the control rod and to these resilient conducting means. The two contacts of one pair of contacts are borne by two pivotable conducting plates, biased by resilient means for connecting the two contacts borne by the conducting plates to their respective terminals. The conducting plates can be pivoted under the action of the control button and against the action of the resilient biasing means for disconnecting the two contacts borne by the conducting plates from their respective terminals.

Abstract: A condition responsive electrical switch construction having a frame carrying an electrical switch and a condition responsive device having a movable wall for causing movement of a lever that is pivotally carried by the frame and is operatively associated with the switch to operate the same as the lever is moved by the wall to a certain position in opposition to the force of a range spring also carried by the frame. A cradle-like member has a base operatively associated with the range spring so as to be held thereby against the wall to be moved in unison with the wall and has arms engaging the lever to cause the lever to move in relation to movement of the wall. The switch has a pair of movable contact members disposed on opposite sides of a fixed contact member and each is biased in a direction to tend to place the same in contact with the fixed contact member and each having an offset loop therein.

Abstract: A trigger switch for portable tools that provides safety disconnect under contact-weld conditions. The switch is a manual close, return spring open, double-snap type wherein the actuator acts on a double-inclined surface of a cam to snap the switch contacts closed or open as the actuator passes the center high point of the cam in one direction or the other. The safety disconnect feature provides in series with the switch contacts a connector biased to flip open that is normally held closed by actuator reactance force on the cam in combination with tripping means therefor. This tripping means includes coacting means between the cam and a contact carrier on which the cam is normally spring-restrained from shifting in the switch opening movement direction of the actuator.

Abstract: An actuating mechanism for a vacuum interrupter incorporates a pivotable bell crank mechanism and a displacement structure for imparting movement of the bell crank mechanism to a coupling structure which is connectable to a contact stem carrying the movable contact of the interrupter for moving the contact into and out of engagement with another contact of the interrupter. After movement of the coupling structure for a sufficient distance in a direction which causes closure of the contacts the displacement structure is capable of being moved for a further distance to disengage it from a cooperating surface of the coupling structure. On the return movement the displacement structure is traveling at high velocity when it re-engages the cooperating surface of the coupling structure which produces a rapid acceleration of the latter and hence, in use, of the movable contact of the interrupter to the open position.

Abstract: An over-center toggle switch suitable for use in an electrical distribution transformer as a series-multiple switch or as a no-load tap changer switch. The over-center toggle switch imparts snap action rotation to a movable contact assembly and, further, cams the movable contact assembly immediately prior to the snap action movement thereby causing an initial rotation of the movable contact assembly. In multiple phase distribution transformers, individual over-center toggle switches are associated with each phase and are interconnected by suitable connecting means to an operating mechanism whereby rotation of the operating mechanism through a predetermined angle causes independent operation of each over-center toggle switch which thereby imparts camming and snap action rotation to the movable contact assemblies in each phase of the distribution transformer.

Abstract: The mechanism enables normal separation of the contacts when the handle is moved, even if the contacts are lightly welded together. This prevents the handle from moving if they are solidly welded together. A toggle joint is included between the drive member for the moving contacts and the automatic trip mechanism. The shaft of the toggle is engaged in an opening in an articulated arm.

Abstract: The present invention relates to an improved breaker point assembly for use with automobile internal combustion engines and the like comprising an improved cam assembly for moving a breaker arm assembly to provide more efficient contact engagement by preventing contact pitting and welding of the contacts together. The breaker arm assembly is pivotally mounted to a tapered post to allow upward movement of the breaker arm. Spring biasing means restrains movement of the breaker arm and the force of the spring biasing means is overcome by the resultant force due to cam, cam follower engagement, such force being greater than the downward force applied by the spring biasing means to the contact breaker arm.

Abstract: A combined thermostatic switch and tilt switch is disclosed which is of the stack type with slow make and break contacts. A temperature responsive element such as a bimetal actuates a set of contacts and an attitude responsive means such as a swingable pendulum also actuates a set of contacts. These two responsive means may actuate the same set of contacts or may actuate different sets of contacts in various embodiments of the invention, but a second set of contacts is provided in the switch as a standby set of contacts which may be actuated by one of the responsive means in the event that the first set of contacts fails to be actuated, e.g. by being welded together or some other malfunction. The foregoing abstract is merely a resume of one general application, is not a complete discussion of all principles of operation or applications, and is not to be construed as a limitation on the scope of the claimed subject matter.

Abstract: A switch including a housing carrying a first contact defining a first fulcrum and having an elongated electrically conductive lever blade disposed in overlying relationship and carrying a second contact from one end thereof for normally engaging such first contact. A third contact is carried from the opposite end of such blade and is movable through a predetermined path to engage a fourth contact carried from the housing and defining a second fulcrum. Biasing means is provided for normally biasing the second and third contacts into engagement with the respective first and fourth contacts. An actuator is operative to overcome such biasing means to disengage the second contact from the first contact and is further operative to, in case the first and second contacts become welded together, sufficiently overcome such biasing means to disengage the third and fourth contacts.