RU2167464C1 - Circuit breaker trip-free mechanism - Google Patents

Abstract

FIELD: manufacture of circuit-opening devices. SUBSTANCE: trip-free mechanism designed for use in fast-response current-limiting circuit breakers rated up to 63 A has handle with grip and base mounted on pin held tight against case by means of spring for its turning; U-shaped double-arm lever with its center supported by axial projections of case; power spring; it is also provided with [-shaped plastic strap with two flanges and hole in central part; strap is placed on movable contact holder loosely mounted on common pin so that one of its flanges embraces yoke and other one, arm of U-shaped lever so as to form, together with disconnecting rack, working clearance sufficient for its engagement as soon as power-circuit contacts break in manual OFF-operation. Reliable disconnection of current circuit in manual and automatic operations is effected using same kinematic scheme. EFFECT: improved reliability, enlarged functional capabilities with respect to circuit-breaker ratings. 8 dwg

Description

 The invention relates to the field of electrical engineering, in particular to high-speed and current-limiting circuit breakers, in particular to mechanisms of free uncoupling of circuit breakers that provide smooth closure of the main contacts when turned on and momentary dilution when turned off.

 The known design of the mechanism of free uncoupling of the automatic current-limiting circuit breaker Company BBC S161G, Germany, see the Catalog of the German company BROWN BOVERI, 1981

 The free trip mechanism of this switch contains in the metal cheeks a control handle with a handle and a base sitting on an axis together with a spring, a lever from two parallel branches, pivotally connected by ends, one with a common pin with a pull of the base of the control handle made by two parallel branches facing an axis sitting in the holes of the base, and the other - a common axis with a U-shaped shank of a movable contact holder, sitting walls of two oval holes on the round axial protrusions of the cheeks, a power spring, one their butt cheeks resting on the ledge, and the other - by the end of the movable contact carrier, rail breaking, locking release lever creation to him of the support when the engagement.

 The disconnecting rail is made as a two-arm lever, the center mounted with the possibility of a turn on the axial protrusions of the cheeks. The spring of the control handle rests with one mustache on the base of the control handle, and with the other on the arm of the trip bar, which engages with the release lever.

 The release lever is made of a T-shaped two-arm, in one shoulder, sitting on the axial protrusions of the cheeks, with grooves that let the ends of the common pin pass, and with the other shoulder covering the engagement tooth of the disconnecting rail. The common pin is included in the curved slots of the cheeks, which allows it to have one path when turned on and a different path when turned off.

 The release lever, after removing the reference engagement with the trip rail during automatic operation in the “off” state, prevents the trip rail from turning in the opposite direction.

The disadvantages of the free trip mechanism of a known circuit breaker include:
1. The complexity of the design, increased metal consumption and manufacturing accuracy.

 2. The constructive ability of stopping the control handle after disconnecting the main contacts when manually disconnecting the current to disable the mechanism.

 3. The range of application for rated current is limited to 25 A.

 4. Ultimate switching capacity does not exceed 3 kA.

 The mechanism of free uncoupling of a circuit breaker of the VA14 series is also known for the licensed development performed by our organization, the Stavropol All-Russian Research Institute of Electric Equipment, on behalf of the Union State Ministry of Electrotechnology in 1983.

 Automatic circuit breakers of the VA14-26-14 series with the well-known mechanism of free tripping began to be mass-produced in 1985 by the plant of the Moldavian Production Association Elektroapparat in the mountains. Tiraspol according to TU16-641.004-83.

The known mechanism for the free tripping of these switches is produced according to the drawing. (See. Mechanism of free uncoupling. Drawing GLIC. 304555.014 SB, - city of Stavropol, AOOT NIIElektroapparat.)
The free trip mechanism of a known circuit breaker comprises a control handle with a handle and a base sitting together with a spring on an axis in the metal cheeks, a U-shaped lever pivotally connected by ends, one with a common pin with a pull of the base of the control handle, and the other with an axis with a movable shaft contact holder, sitting by the walls of two oval holes on the round axial protrusions of the cheeks, a power spring mounted with one end on the protrusion of the cheeks and the other abutting against the end of the movable contact holder, An insulating two-arm T-arm and a trip bar, which have the possibility of joint support engagement when turned on. The disconnecting rail is installed in the center with the possibility of a turn on the axial protrusions of the cheeks, with one shoulder it can interact with the electromagnetic release when it is triggered, and with the other shoulder it can interact with the thermal release with thermal actuation. The tripping two-arm T-lever sits with one shoulder on the axial protrusions of the cheeks and skips the ends of the common pin with longitudinal grooves, and the gear tooth of the disconnecting rail covers the other shoulder.

 The spring of the control handle with one mustache interacts with the base of the control handle, with the other with a mustache it rests against the shoulder of the disconnecting rail, which engages with the release lever.

 In the cheeks of the free trip mechanism, Δ-shaped grooves are made, which allow the ends of the common pin to pass through, which allows him to use different trajectories when moving to and from switching off and on.

 The design of this free trip mechanism was able to increase the range of applications for the rated current of the circuit breakers up to 32 A.

 However, a further increase in the nominal value of the circuit breaker without an increase in size is problematic with a single gearing of the trip rail with a trip lever, since it leads to an increase in contact pressing force, resetting force of the gear of the trip rail, enlargement of the releases.

In addition, the known mechanism of free trip inherent disadvantages:
1. The complexity of the design, increased metal consumption.

 2. The reliability of manual disconnection of load currents is low.

 3. Dependence of the reliability of disconnection on the actions and physical data of the operator.

 4. The time for overcurrent disconnection during automatic operation is long.

 5. Unreliable alarms when holding the handle and automatically turning off.

 Increased metal consumption is a consequence of the presence of metal cheeks and the manufacture of all parts of the mechanism from metal.

 Low reliability of manual disconnection of load currents, its dependence on the operator is associated with the constructive possibility of stopping the process of breeding contact holders by holding the handle after disconnecting them.

 The duration of the current during automatic shutdown when applying voltage at different angles of industrial frequency voltage in some cases exceeds 10 ms. This is due to the kinematics of the movement of the movable contact carrier. After resetting the engagement of the disconnecting rail with the trip lever, the choice of a failure follows, the movement of the shank of the movable contact holder with oval grooves on the round axial protrusions of the cheeks, and only after the choice of the failure is the separation and separation of the main contacts into a complete solution.

 With the stop holding the handle after automatic shutdown, the handle enters an intermediate position between “on” and “off”. The release lever does not reach the point of engagement with the trip rail. A power spring that exceeds the handle spring by stiffness is not used to move it. To enable it requires preliminary manual sending of the handle to the signal position "off".

 The mechanism of free uncoupling of a multi-pole circuit breaker VA80 is also known. See the patent of the Russian Federation N 2117355, H 01 H 73/02, 1998 Bull. N 22. The installation lot of the VA80 circuit breakers with the well-known free trip mechanism was made by the low-voltage equipment factory in the mountains. Cherkessk.

 The well-known mechanism of free uncoupling of a multi-pole circuit breaker contains in each pole a handle with a handle and a base, spring-loaded on the axis rotatably, a traverse that can interact with the base of the handle, a trip lever with a shank and a contact holder fixed movably on the axis of the traverse, a power spring, latch, locking release lever, two-shoulder lever, mounted with the possibility of interaction with one shoulder with the shank of the release lever, and the other - with a latch, and two common hard mounts, one of which connects the handles of the handles, and the other - the axis of the two-arm levers.

 The handle is made with a faceted base, and the traverse - with a faceted end, facing the edges of the faces to each other and installed with a gap that interrupts the connection of the handle with a movable contact holder, which allows the beginning of the separation of the main contacts during manual shutdown to provide instantly at a distance at which the short arc. The kinematic connection between the elements of the known mechanism of free trip allows you to use the main spring of each pole to fix the handle and its return to the "off" position after automatic operation while holding the handle in the "on" position.

 The mechanism eliminated the constructive possibility of failure when disconnected by holding the handle.

 Nominal current range increased to 40 A.

 Reduced metal consumption and complexity of manufacturing structures.

However, the known free-release mechanism has disadvantages:
1. Small range of application for rated current.

 2. The time of disconnecting the currents of the limit switching is great.

 The range of application of the free trip mechanism for rated current up to 40 A was increased in the VA80 circuit breaker, 1.25 times larger in volume than the VA14 circuit breaker with the same 3 kA maximum switching capacity.

 Further expansion of the range in this volume is unlikely with a single engagement of the release lever with the lock.

 The cut-off time of the limit switching currents can exceed the duration of one half-cycle of the industrial frequency, because the turn on the axis of the movable contact holder and the separation of the main contacts begin only after the traverse reaches the housing stop, i.e. after a complete selection of failure.

 The most miniature, simple in design and rational in terms of material consumption is the free trip mechanism of the VA22-27 circuit breaker, known by the patent of the Russian Federation 2074441, H 01 H 73/18 from 02.27.97.

 The VA22-27 circuit breakers with the well-known free trip mechanism are produced in series by the low-voltage equipment factory in the mountains. Cherkessk. The nominal value of the circuit breaker is 40 A. The depth of the circuit breaker is half the depth of the VA14 circuit breaker.

 The design of the known free trip mechanism provides one trajectory and speed to the movable contact holder both during automatic and manual shutdown.

 A well-known mechanism for the free tripping of a circuit breaker contains a power button, a trip button, a traverse made by a flat trident, a tripping lever with a pinch and two longitudinal grooves running one after the other along the horizontal axis, a latch serving as a rotary anchor, with a meshing window for a tripping rotary lever , a spring-loaded lever with a clutch tooth for a cross-arm mounted between a rotary arm and a trip lever for the possibility of interaction with the latter after failure wa first gearing, power spring. The mechanism has two gears.

 The release pivot arm engages with one end on the latch, and is placed on the movable contact holder at the other end with a pinch. The traverse end enters the power button, the rotary release lever and the movable contact holder penetrate the extreme teeth, and the central tooth is pressed against the rotary release lever between the longitudinal grooves, one extreme tooth freely enters the power spring, and the other extreme tooth engages with the spring-loaded lever.

 The presence of two gears in the mechanism removes the problem of increasing the nominal value of the circuit breaker in the minimum dimensions, or without increasing the dimensions.

 The presence of two control buttons, two gears, the connection of the power button through the central tooth of the traverse with a rotary trip lever ensures the independence of automatic, manual disconnection of currents and the moving contact holder to complete solution from holding the inclusion command. The movement of the pivoting release lever after the first engagement is disengaged is used to remove the second engagement.

The known mechanism of free trip has the disadvantages:
1. The time for automatic shutdown of the currents of the limit switching is long. It is 12-16 ms at a current value of 3 kA for cases when it changes direction from start-up to disconnect contact holders.

 2. The long tripping time and the ambiguity of the response characteristics are caused by the phenomena of weak welding, delaying the reset of the second engagement, the time of the choice of the failure by the contact holder.

 The elimination of these shortcomings by improving the design, improving the kinematics allowed us to create a mechanism for the free tripping of a current-limiting circuit breaker, known according to the patent of the Russian Federation 2117356, H 01 H 73/18, publ. Bull. N 22, 1998

The free trip mechanism of this switch contains a power button, a power button, a trident traverse, an end included in the power button, a trip lever that disengages the rail with the engagement window for it and with a notch, a spring-loaded lever with a longitudinal hole mounted on an axis between the disconnecting rail and with a swinging release lever $\genfrac{}{}{0ex}{}{\text{┌}}{\text{└}}$ -shaped traction, covering the branches, entering the ends of the branches, respectively, into the hole of the spring-loaded lever and the notch of the disconnecting rail and connecting them, the power spring. $\genfrac{}{}{0ex}{}{\text{┌}}{\text{└}}$ -shaped rod covers the pivoting armature and the spring-loaded lever so that the distance difference between the spanning branches and the covered sides of the spring-loaded lever and the trip rail made by the pivot arm is greater than the engagement of the pivoting trip arm with the trip bar and less than the air working clearance of the magnetic circuit of the electromagnetic release.

 Two gears and their simultaneous uncoupling during automatic operation make it possible to disconnect the contact holders earlier, without selecting a failure.

 Simultaneously with the movement along with the traverse, the turn of the movable contact holder at the central tooth of the traverse allows a circuit breaker with a well-known free trip mechanism to disconnect the maximum switching currents of 3 kA for a time of no more than 5-7 ms at any angle of switching on the voltage of the industrial frequency.

 The well-known domestic circuit breaker with this free trip mechanism is the smallest in volume, material consumption, in comparison with circuit breakers with a nominal value of 40 A from the CIS countries and Europe.

However, the known free trip mechanism has disadvantages:
1. The small volumes and sizes of nodes and parts make it difficult to increase the ultimate switching capacity of circuit breakers with this mechanism.

 2. It is difficult to make versions with different or equal settings of magnetic operation with constant ampere-turns for the provided series of rated currents.

 3. Two control buttons.

 In another well-known VM40 circuit breaker, having a free trip mechanism similar to the previous one, it was possible, by increasing the volume and using a reduced-sized solenoid coil with the removal of the return spring of the electromagnetic release to its additional pusher, pressing the firing pin to the armature, to obtain versions with different and identical response rates with an unchanged number of turns for a number of rated currents, increase the maximum switching capacity.

 The known design of the free trip mechanism of the VM40 circuit breaker is the closest in technical essence to the claimed one.

 It finds application in single-pole and multi-pole versions assembled from a single-pole VM40 circuit breaker, commercially available in the mountains. Kursk according to the patent of the Russian Federation 2115975, H 01 H 73/48, 1998, Bull. N 20.

 The well-known mechanism for the free trip of the circuit breaker, selected for the prototype, contains in the pole housing a control handle with a handle and a base, sitting with the spring on the same axis with the possibility of a turn, a two-arm U-shaped lever, which is centered on the axial protrusions of the housing, hinged by the shoulders, one through a rod with the base of the control handle, and the other through a common axis with a movable contact holder and a traverse, a power spring that disconnects the spring-loaded rack, and a two-arm lever that sits on rim on the axis in the housing, with the ability to create two gears with both shoulders, one with a spring-loaded disconnecting rail, and the other shoulder with a traverse of the movable contact holder.

 The advantage of the well-known design of the free trip mechanism of a circuit breaker selected as a prototype is its increased speed, overcurrent disconnection during magnetic tripping in no more than 10 ms.

 Switches with the known design of the free trip mechanism provide switching with current limitation and low time at all angles of the voltage wave provided for the industrial frequency. (See GOST R 50345-92, Circuit Breakers for Overcurrent Protection for Domestic and Similar Purpose, p. 51, introduction date 01/01/94).

 They have a relatively high limit switching capacity - 4500 A.

 The positive effect of speed and current limitation is provided by the rational kinematics of the free trip mechanism during automatic shutdown, using almost simultaneous reset of two locking gears to release the energy of the power spring and the spring of the control handle. Rational kinematics allows the separation of the main contacts without the choice of failure.

 When a command is sent to automatically turn off and hold the command to turn on, despite the chain of one-piece articulation of the control handle with the movable contact holder, the free trip mechanism ensures that the movable contact holder comes to a complete solution.

However, the mechanism of free trip, selected for the prototype, has inherent disadvantages:
Reliability of disconnecting currents is low when a command is issued for disconnecting by the control handle and manual operation.

 Dependence of the reliability of non-automatic shutdown on the physical data of the operator, affecting the speed and time of dilution by the main contact mechanism.

 With manual operation, the process of returning the movable contact holder from the final state “on” to the initial state “disconnected” is carried out without releasing gears.

 Since the base of the control handle is inextricably pivotally connected to the movable contact holder via a rod, two-armed U-shaped lever and a common axis, at any time when choosing a solution with the operator holding the handle, the contact holder withdrawal stops, the use of spring energy is suspended.

 The constructive ability to stop the handle of the control handle after disconnecting the main contacts, returning it to the on position and manipulating between these positions.

 Holding the handle of the control handle when the movable contact holder selects a portion of the solution under the current load that is insufficient to extinguish the electric arc leads to the failure of the free trip mechanism by burning the main contacts.

 The return of the handle of the control handle to the “on” position after preliminary disconnection of the contact holders, warming up to reflow by the arc during the retention time, leads to their welding upon contact.

 The manipulation by the handle of the control handle between the holding position and the “on” position provides the pendulum mode to the movable contact holder, which does not turn off the current, and is fraught with welding or burning of the main contacts.

 In connection with the foregoing, the reliability of disconnecting currents during manual operation decreases with an increase in the nominal value of the circuit breaker, which limits the range of application of the free trip mechanism selected for the prototype. So, the nominal value of the VM40 circuit breaker is 40 A.

 The proposed technical solution finds a way to eliminate or reduce the listed design deficiencies of the known mechanism of free tripping of a circuit breaker.

 Namely: to increase the reliability of disconnecting currents during manual operation, to ensure its independence from physical data and operator actions, to exclude the constructive ability to disable the mechanism by holding and manipulating the handle of the control handle, to expand the range of applications for rated current.

 The essence of the invention lies in the fact that without changing the chain of articulation of the control handle with a movable contact holder, to improve the kinematics of the mechanism during manual operation, provide for the release of energy from the power spring after loss of contact of the main contacts and use it as an independent drive to output the movable contact holder to a complete solution, in including under certain conditions of holding the handle of the control handle.

 In other words, the essence of the invention lies in the fact that in any conditions of manual control, after separation of the main contacts, to provide an independent process of their dilution into a complete solution with the energy accumulated by the power spring before the start of switching.

 The aforementioned becomes feasible with the addition of the free trip mechanism in only one pole of the circuit breaker for both multi-pole and single-pole versions by an element that changes its kinematics in the direction of using the power spring to independently move the movable contact holder after losing contact with the stationary contact in the initial position "disconnected".

 In addition, the aforementioned becomes feasible with the introduction of a movable contact holder and a two-arm U-shaped lever connected to a common axis movable in the housing with a movable contact holder, introducing new functions, using the trajectories of their movements: traverses - to move the inserted element until it disengages the spring-loaded contact racks with a release lever for manual shutdown; U-shaped two-shouldered lever - to return the input element to its original state when manually turned on.

To implement the proposed technical solution according to the invention, the free trip mechanism of the circuit breaker is provided $\genfrac{}{}{0ex}{}{\text{┌}}{\text{└}}$ -shaped bracket $\genfrac{}{}{0ex}{}{\text{┌}}{\text{└}}$ -shaped bracket made of a plate with a hole in the central part, placed by the central part on a movable contact holder and freely mounted on a common axis connecting the articulated movable contact holder with a traverse and a shoulder of a U-shaped two-shouldered lever.

Wherein $\genfrac{}{}{0ex}{}{\text{┌}}{\text{└}}$ -shaped bracket with the end of the central part adjacent to the end of the traverse, and with bends covers: one - the shoulder of the U-shaped lever, the other - the traverse of the movable contact holder. Limb $\genfrac{}{}{0ex}{}{\text{┌}}{\text{└}}$ -shaped brackets, covering the traverse of the movable contact holder, forms a working gap with a disconnecting spring-loaded rail of such magnitude that it interacts with it after a manual shutdown command from the moment the main contacts are disconnected.

Such an addition to the free trip mechanism $\genfrac{}{}{0ex}{}{\text{┌}}{\text{└}}$ -shaped bracket creates the conditions for reliable reset by one limb of the engagement of the disconnecting spring-loaded rack with the trip lever and the release of energy of the power spring immediately after the separation of the main contacts.

Further limb $\genfrac{}{}{0ex}{}{\text{┌}}{\text{└}}$ -shaped staples, having reset the engagement, does not impede the engagement of the release lever, which disables the spring-loaded rail of the initial positions associated with the moving contact holder to full solution. And when manually turned on $\genfrac{}{}{0ex}{}{\text{┌}}{\text{└}}$ -shaped bracket, interacting with another bend with the shoulder of the two-shouldered U-shaped lever, unfolds on the common axis to the initial position, its bend, covering the crosshead of the movable contact holder, goes beyond the disconnecting spring-loaded rail without displacing it and restores the working clearance a.

The process of moving contact holders to full solution in other poles in the case of a multi-pole design of a circuit breaker is carried out due to the energy of the power spring of each pole released during discharge $\genfrac{}{}{0ex}{}{\text{┌}}{\text{└}}$ -shaped clutch of disengaging spring-loaded rails with trip levers, because with multi-pole design the axes of the locking disconnecting rails are connected by slats.

 The termination of the holding of the handle of the control handle releases the energy of its spring, causes it to turn “off” at the axis to its original position, turn the release lever on the fixed axis until one of its shoulders leaves the surface of the disconnecting spring-loaded rack to the engagement point and the traverse of the movable contact carrier is covered by the other shoulder.

 The handles of the control levers of the mechanisms of free uncoupling of the multi-pole circuit breaker are connected by rigid common fastening, therefore, the process of their release to the signal position is “manually or automatically disabled” with the cessation of holding is identical.

 A comparative analysis of the listed differences of the claimed mechanism for the free trip of the circuit breaker from the prototype confirms compliance with the criteria of the invention of "novelty."

 The comparison we made with the prototype and other solutions in the field of electrical apparatus allows us to conclude that the proposed solution meets the criterion of "significant differences".

 The invention is illustrated by drawings.

 In FIG. 1 shows the proposed mechanism for the free trip of the circuit breaker in the "on" state.

In FIG. 2 is depicted in two projections $\genfrac{}{}{0ex}{}{\text{┌}}{\text{└}}$ -shaped plate bracket of the proposed free trip mechanism.

 In FIG. 3 - the proposed mechanism of free uncoupling in the "dead" position of the nodes playing the role of breaking arms.

 In FIG. 4, 4a - the proposed mechanism for the free trip of the circuit breaker during manual shutdown from the "on" state while holding the handle of the control handle.

 In FIG. 5 - the same in the "disabled manually or automatically" state.

 In FIG. 6 is a proposed free trip mechanism in the case of a bipolar design of a circuit breaker, end view.

 In FIG. 7 - the proposed free trip mechanism in the housing of the VA81-29 circuit breaker of a nominal value of 63 A, the cover is removed.

The proposed mechanism for the free uncoupling of the circuit breaker contains a control handle 1 with a handle 2 and a base 3, sitting on the axis 4 with a spring 5, pressing it against the housing 6 with the possibility of a turn, two shoulders U-shaped lever 7, based on the axial protrusions 8 of the housing 6, a shoulder 9 pivotally connected by a thrust 10 with the base 3 of the control handle 1, and a shoulder 11 having a pivot connection through a common axis 12 with a movable contact holder 13, $\genfrac{}{}{0ex}{}{\text{┌}}{\text{└}}$ -shaped plate bracket 14, made with a hole 15 in the central part and two bends 16 and 17, and with a traverse 18 of the movable contact holder, a power spring 19 that disconnects the spring-loaded rack 20 and the uncoupling two-arm lever 21, freely sitting on the axis 22 that is stationary in the housing, a shoulder 23 having the ability to engage with a disconnecting spring-loaded rail 20, and a shoulder 24 - with the traverse 18 of the movable contact holder (Fig. 1, Fig. 2).

Traverse 18, covering the free end 25 of the movable contact holder 13, the movable contact holder 13 and $\genfrac{}{}{0ex}{}{\text{┌}}{\text{└}}$ - the shaped plate bracket 14 is mounted freely on a common with the shoulder 11 two-shouldered U-shaped lever 7 of the movable axis 12 with the possibility of movement with it and a turn.

Wherein $\genfrac{}{}{0ex}{}{\text{┌}}{\text{└}}$ -shaped plate clamp 14 with the central part placed on the movable contact holder 13 and the end face 26 of the central part adjacent to the end face 27 of the yoke 18, with one bend 16 it covers the yoke 18 and forms a working gap and with the spring-loaded rail 20 disconnected, the other bend 17 - the U-shaped shoulder 11 two shoulders lever 7.

The size of the working gap and between the limb 16 $\genfrac{}{}{0ex}{}{\text{┌}}{\text{└}}$ -shaped plate staples 14 and disconnecting spring-loaded rail 20 is structurally determined by the beginning of their interaction with the loss of contact of the main circuit contacts during manual shutdown.

 The proposed mechanism for the free trip of the circuit breaker operates as follows.

 When manually operating from the final state, it is “on”.

 The final state "on" is characterized by the presence of stored energy in the power springs 19, contact pressing 28 and the spring 5 of the control handle 1 (Fig. 1; Fig. 7). The contact pressing spring is shown in FIG. 5.

 The movable contact holder 13 at one end supports contact with the fixed contact holder 29, the other free end 25 through the contact pressing spring 28 and the yoke 18 rests on the shoulder 24 of the two-arm release lever 21, forming a reference engagement.

 The end face 27 of the traverse 18 forms a gap b with the end 30 of the free end 25 of the movable contact holder 13. The other shoulder 23 of the two-arm releasing lever 21 is in reference engagement with the disconnecting spring-loaded rail 20.

 The handle 2 of the control handle 1 is in the highest signal position. Its base 3 is pivotally connected by a thrust 10 with a shoulder 9 of a two-shouldered U-shaped lever 7 in a position in which the center of the hole in the base 3 passing the rod 10 lies above the straight line connecting the center axis of the control handle 1 with the center of the hole with the rod in the shoulder 9, those. for the "dead" position. (In Figs. 1, 3, the straight line is shown with a dashed line).

 The base 3 of the control handle 1 with a thrust of 10 carry the function of breaking arms. Without translating the end of the rod 10, passed into the hole of the base 3 of the control handle 1 through the "dead" position, it is impossible to release the energy of the springs to disconnect and separate the main contacts.

 The operator’s effort applied to the handle 2 (Fig. 4; the dotted line corresponds to Fig. 1) is summed up with the force of the compressed spring 5 of the control handle 1. Upon reaching the set value, the operating force is sufficient to start turning the control handle 1 on the axis clockwise . Her handle 2 moves away from the wall of the housing 6, and the base 3 transfers the end of the rod 10 to the "dead" position (Fig. 3).

 The transfer of the end of the thrust 10 to the “dead” position is accompanied by a small turn of the two-shouldered U-shaped lever 7 at the axial projections 8 of the housing 6 in a clockwise direction, i.e. in the opposite direction to the disconnection of the main contacts.

 The shoulder 11 of the two-shouldered U-shaped lever 7 transfers the common axis 12 in the direction of the contact plane of the main contacts. The displacement of the common axis 12 causes additional deformation of the contact pressing spring 28 in the traverse 18, an increase in the gap b at one end 25 of the movable contact holder 13 and an increase in the contact force at the other end.

The movable contact holder 13 is rotated at the fixed contact holder 29. The supporting engagement forces of both arms 23 and 24 of the trip arm 21 increase. Working clearance a between the limb 16 $\genfrac{}{}{0ex}{}{\text{┌}}{\text{└}}$ -shaped bracket 14 and disconnecting spring-loaded rail 20 increases (Fig. 3).

 With manual maintenance of the necessary magnitude of the operating effort, the control handle 1 continues to turn, transferring the end of the rod 10 to the “dead” position with the base 3. The exit of the center of the hole of the base 3 with the end of the rod 10 for the "dead" position releases the energy of the spring 5 of the control handle 1.

Further reversal does not require operator involvement. The force of the spring 5 begins the reversal of the two shoulders of the U-shaped lever 7 at the axial protrusions 8 of the housing 6 counterclockwise and continues to turn the control handle 1 in the direction of shutdown. The two-armed U-shaped lever 7 first goes through the state in which it was before manual operation, its shoulder 9 transfers the common axis 12 in the direction of separation of the contact holders 13 and 29. Contact pressing, supporting forces of both gears of the uncoupling two-armed lever 7 return to the initial values between the end 27 of the beam 18 and the end 30 of the free end 25 of the movable contact holder 13 and the working gap a between the limb 16 $\genfrac{}{}{0ex}{}{\text{┌}}{\text{└}}$ -shaped plate staples 14 and disconnecting spring-loaded rail 20.

 The movable contact holder 13 is deployed at the engagement of the yoke 18 with the arm 24 of the tripping two shoulder arm 21. With the displacement of the common axis 12 and the rotation of the movable contact holder 13 at the engagement of the yoke 18 with the arm of the trip arm 21, the contact pressure decreases.

Because $\genfrac{}{}{0ex}{}{\text{┌}}{\text{└}}$ -shaped bracket 14 is made lamellar, with a hole 15 in the central part, placed by the central part on the movable contact holder 13 and passes the common axis 12 through this hole, then it moves with the common axis 12 in the direction of the spring-loaded rail 20, reducing the working gap a between the bend 16 covering the crosshead 18, and disconnecting the spring-loaded rail 20. Having selected the failure, the movable contact holder 13 loses contact with the stationary 29, and the limb 16 $\genfrac{}{}{0ex}{}{\text{┌}}{\text{└}}$ -shaped bracket 14, choosing a working gap a, interacts support with a disconnecting spring-loaded rail 20. Support interaction of the bend $\genfrac{}{}{0ex}{}{\text{┌}}{\text{└}}$ -shaped bracket with disconnecting spring-loaded rail 20 leads to a turn of the latter on its axis, because $\genfrac{}{}{0ex}{}{\text{┌}}{\text{└}}$ -shaped bracket with the end face 26 of the central part abuts against the end face 27 of the beam 18, which excludes the possibility of its turning around the common axis 12 in a clockwise direction. Turning on the clockwise axis, the disconnecting spring-loaded rail 20 loses engagement with the shoulder 23 of the release lever 21, releases the energy of the power spring 19. By the force of the power spring 19 applied to the protrusion 31 of the yoke 18, it rotates counterclockwise on the common axis 12 until the gap b is selected and reaching its end 27 of the end 30 of the free end 25 of the movable contact holder 13 (Fig. 4). (The gap b, the ends 27 and 30 see in Fig. 7).

 The traverse 18, acting on the shoulder 24, with the total force of the contact pressing spring 28 and the power spring 19, sharply expands the two-arm lever 21 on its axis 22 clockwise and loses engagement with it.

 Keeping from further turning the control handle 1 by the operator stopping the handle 2 does not prevent the continuation of the turning at the common axis 12 of the movable contact holder 13 by the force of the power spring 19 until it reaches a complete solution in (Fig. 4a).

 The manipulation of the handle 2 of the control handle 1 between the “on” and “hold” positions after resetting the support gears of the arms 23 and 24 of the trip two-arm lever 21 does not affect the shutdown process, because It is impossible to send the movable contact holder 13 to the stationary one without the support gears.

If the retention of the handle 2 of the control handle 1 continues after the movable contact holder 13 is in full solution to the stop 32, then the shoulder 23 of the two-arm release lever 21 abuts against the surface 33 of the disconnecting spring-loaded rack 20, and the bend 16 $\genfrac{}{}{0ex}{}{\text{┌}}{\text{└}}$ -shaped bracket 14 is located above its surface 33 (Fig. 4A).

 The termination of the holding of the handle 2 is followed by the continuation of the turning by the spring 5 of the control handle 1 of the two-shouldered U-shaped lever 7 and the displacement of the common axis 12 in the previous direction. The movable contact holder 13 with one end that has reached the full solution is rotated at the point of contact at the stop 32, and with the other end 25 with the traverse 18 it reaches shoulder 23 and turns counterclockwise two-arm lever 21 at its axis 22 counterclockwise.

 One shoulder 23 of the two-shouldered release lever 21 leaves the surface 33 of the disengaging spring-loaded rail 20, and the other shoulder 24 covers the yoke 18. The exit of the shoulder 23 of the two-shouldered release lever 21 beyond the surface 33 of the disconnecting spring-loaded rack 20 is accompanied by its own spring 34 turning to the initial state, wherein the surface 33 of the disconnecting spring-loaded rail 20 lies above the end face 35 of the arm 23. The handle 2 of the control handle 1 occupies an extreme signal position.

 The free-release mechanism of the circuit breaker comes to the initial state “disabled manually or automatically”, FIG. 5.

Manual disconnection of a multi-pole circuit breaker with retention of the general fastening of 36 handles 2 is identical, because the axis of the disconnecting spring-loaded rails 20 of the mechanisms of free uncoupling are connected by straps 37 (Fig. 6). Moreover, the installation $\genfrac{}{}{0ex}{}{\text{┌}}{\text{└}}$ -shaped plate staples 14 at any one pole is sufficient for reliable tripping of a multi-pole circuit breaker.

 When manually operating from the initial state, it is "disabled manually or automatically" to the final "enabled".

 In the initial state, manually or automatically, the movable contact holder 13 is pressed by the power spring 19 against the stop 32. One arm 24 of the tripping two-arm lever 21 is freely covered to form a gap g of the yoke 18 of the movable contact holder 13, and the other arm 23 is in contact with it and is also freely covered disconnecting spring-loaded rail 20 with the formation of a gap d, FIG. 5.

Bend 16 $\genfrac{}{}{0ex}{}{\text{┌}}{\text{└}}$ -shaped plate bracket 14 is located between the arm 23 of the trip lever and the disconnecting spring-loaded rail 20 above its surface 33.

 The yoke 18 is deployed by the force of the contact pressing spring 28 on the common axis 12 relative to the movable contact holder 13. On one side, it contacts the shoulder 23 of the two-shoulder release lever 21, and the butt 27 of the other side is adjacent to the end 30 of the free end 25 of the movable contact holder 13. Ends 27 and 30 are shown in FIG. 7.

 By the force of the operator applied to the handle 2, the control handle 1 is rotated on the axis 4 counterclockwise.

The base 3 carries the end of the rod 10 in the direction of the "dead" position. The rod 10 over the shoulder 9 turns the two-arm U-shaped lever 7 at the axial protrusions 8 of the housing 6 in a clockwise direction. Shoulder 11 two shoulders U-shaped lever 7 transfers the common axis 12 with a movable contact holder 13, a traverse 18 and $\genfrac{}{}{0ex}{}{\text{┌}}{\text{└}}$ -shaped bracket 14 in the direction of connection of the main contacts. However, at the beginning of the transfer of the common axis 12, the solution does not decrease, because the end 25 of the movable contact holder 13 with the traverse 18 have a gap r with the covering arm 24 of the tripping two-arm lever 21, until which the other end of the movable contact holder 13, turning at the stop 32, does not leave it.

 The yoke 18 loses contact with the shoulder 23 and, in continuing the transfer of the common axis 12, reaching the shoulder 24, unrolls the two-arm lever 21 at the axis 22 in a clockwise direction. The shoulder 23 at the same time, having chosen the gap d, is in contact with the disconnecting spring-loaded rail 20 enclosing it.

 The restoration of the reference engagement of the yoke 18 with the shoulder 24 of the tripping two-arm lever 21 makes it possible to turn the movable contact holder 13 in place of the reference engagement.

 The presence of support engagement of the shoulder 23 of the two-arm release arm 21 with the spring-loaded disconnecting rail allows the movable contact holder 13 to come closer to the stationary contact holder 29, and the power spring 19 to accumulate deformation energy.

 When the end of the rod 10, moved by the base 3, reaches the proximity of the "dead" position, the movable contact holder 13 is in contact with the stationary contact holder 29, thereby eliminating the possibility of its further rotation in the place of engagement.

-образную пластинчатую скобу 14 у общей оси 12 по часовой стрелке. При нахождении конца тяги 10, входящего в отверстие основания 3 рукоятки управления 1, в "мертвом" положении отгиб 16, выйдя за край отключающей подпружиненной рейки 20, образует с ней зазор а.Bend 16 $\genfrac{}{}{0ex}{}{\text{┌}}{\text{└}}$ -shaped plate staples 14, driven by a common axis 12, moving above the surface 33 of the disconnecting spring-loaded rails 20, reaches its edge. With another limb 17, the shoulder 11 of the two-shouldered U-shaped lever 7 begins to interact, turning

-shaped plate bracket 14 at the common axis 12 clockwise. When the end of the rod 10, which enters the hole in the base 3 of the control handle 1, is in the "dead" position, the limb 16, going beyond the edge of the disconnecting spring-loaded rack 20, forms a gap a with it.

The exit of the limb 16 beyond the edge of the disconnecting spring-loaded rail 20 does not lead to its rotation even in the case of touching the surface 33, because $\genfrac{}{}{0ex}{}{\text{┌}}{\text{└}}$ -shaped plate bracket 14 is free to turn counterclockwise on a common axis 12.

 In the "dead" position, the deformation forces of the contact pressing spring 28 and the power spring 19 are greatest.

 The transition of the "dead" position of the end of the rod 10 and the base 3 of the control handle, playing the role of breaking arms, completes the inclusion process.

 The handle 2 of the control handle 1 occupies the extreme signal position "on". The spring 5 of the control handle 1 and the power spring 19 are maximally deformed. The common axis 12 is biased towards the disconnecting spring-loaded rack 20 in comparison with its place in the "dead" position of the breaking arms. By this displacement of the common axis 12, following the transition of the breaking levers of the "dead" position, the force of the contact pressing spring 28, the forces of both supporting gears of the tripping two-arm lever 21 and the gap b between the end 30 of the free end 25 of the movable contact holder 13 and the end face 27 are restored to nominal values 18, determining the magnitude of the failure of the contacts of the main circuit (Fig. 1, Fig. 7).

 In the automatic overcurrent disconnection mode, the movable contact holder 13 of the proposed free trip mechanism is rotated by the power spring 19 at the common axis 12 and transferred by the spring 5 of the control handle 1 together with the common axis 12 in the direction of the solution choice.

The proposed free trip mechanism operates without requiring additional measures when changing relative to the vertical position of the circuit breaker on the panel. Independence of restoration of a working gap and between a limb 16 $\genfrac{}{}{0ex}{}{\text{┌}}{\text{└}}$ -shaped plate brackets 14 and disconnecting spring-loaded rail 20 from the location of the circuit breaker is provided in that the trajectory of the traverse 18 is used to turn the disconnecting spring-loaded rack 20 with the bend 16 for manual shutdown, and the shoulder path 11 is used to restore the working gap and when turned on by another bend 17 two-shouldered U-shaped lever 7. The used trajectories of movements vary in length.

The proposed free trip mechanism of the circuit breaker has advantages over the prototype:
- Higher reliability of disconnection of currents when giving a command to disconnect the control handle in both single-pole and multi-pole versions.

 - The disconnection of currents during manual operation does not depend on the speed of movement of the handle and its stop holding.

 - It has no constructive possibility of incapacitation by manipulating the control handle.

 - Disconnection of currents after giving the command to disconnect the handle is automatic, using the power spring and the handle spring.

 - It has a wider range of applications for the nominal value of the switch, up to 63 A.

 On the proposed free trip mechanism, drawings have been developed for the VA81-29 circuit breaker with a nominal value of 63 A.

 Production is being prepared for the serial production of the VA81-29 circuit breaker.

Claims (1)

 A free-release mechanism of a circuit breaker, comprising a control handle with a handle and a base, sitting on an axis with a spring, which can be pivoted against the housing, a two-armed U-shaped lever, centered on the axial protrusions of the housing, hinged by the shoulders, one - by a rod with the base control handles, and the other - a common axis with a movable contact holder and its traverse, a power spring that disconnects the spring-loaded rack and the two-arm release lever, which sits freely on the axis in the housing, one shoulder having the ability to engage with the disconnecting spring-loaded rail, and the other shoulder with the traverse of the movable contact holder, characterized in that it is equipped with an [-shaped bracket, which is made of a plate with two bends and with a hole in the central part, placed by the central part on the movable contact holder and it is freely mounted on its axis common with the shoulder of the two-shouldered U-shaped lever so that it covers the shoulder of the two-shouldered U-shaped lever with one limb, the traverse of the movable contact holder with the other, and the end face The central part is adjacent to the end of the traverse, while the bend covering the traverse of the movable contact holder forms a working gap with a disconnecting spring-loaded rail of such a magnitude that interaction with it occurs with the loss of contact of the main circuit contacts during manual shutdown.

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