Classifications

• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
  • H01H3/00—Mechanisms for operating contacts
  • H01H3/60—Mechanical arrangements for preventing or damping vibration or shock
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
  • H01H9/00—Details of switching devices, not covered by groups H01H1/00 - H01H7/00
  • H01H9/30—Means for extinguishing or preventing arc between current-carrying parts
  • H01H9/32—Insulating body insertable between contacts

Definitions

• the present invention relates to an electromechanical protection switch device with intensity threshold.
• Such a switching device includes in an enclosure an interruptible electrical circuit which includes a magnetic trip device, at least one separable fixed contact and one movable contact, as well as an arc breaking screen interposable between the contacts during a separation of the latter caused by implementing the magnetic trip device in response to an overcurrent or a short circuit.
• an interruptible electrical circuit which includes a magnetic trip device, at least one separable fixed contact and one movable contact, as well as an arc breaking screen interposable between the contacts during a separation of the latter caused by implementing the magnetic trip device in response to an overcurrent or a short circuit.
• French patent 2,540,665 there is also described such an apparatus in which the screen has a front surface capable of being applied at the end of the race against a stop of the housing.
• the arc cut-off screen is projected at high speed towards its stop by the plunger of the magnetic trip device. It reaches its stop with a very high speed, sometimes greater than 20 m / s, and with a sharp acceleration, likely to exceed 400g. This is particularly observed at the periphery of rotary cut-off screens.
• the screen therefore risks either breaking the stop or breaking itself. If the screen and / or its stop are reinforced, the screen may rebound and allow the arc phenomenon to remain, which affects the operation of the device and its longevity. In addition, such a reinforcement leads to an additional bulk, which is unfortunate in the case of a modular device.
• the object of the invention is to overcome these drawbacks and to prevent the continuation of the arc phenomenon as soon as it has been destabilized by the cut-off screen, using simple means, compact and efficient. It also aims to simply integrate these means into the housing of the device.
• the stop associated with the housing for receiving the cut-off screen is deformable.
• the stop is preferably at least partially elastic and arranged not to immediately restore to the cut-off screen the kinetic energy received from it, the delay in restoring this energy being determined so that the return of the screen only occurs after the arc is completely extinguished.
• the stop can advantageously be attached to a part of the housing of the device and come from molding with this part; to balance the reaction on the screen, provision is preferably made for two deformable stops arranged opposite one another on two mutually assembled parts of the housing.
• the deformable stop can have at least two zones of different elasticity, the zone of higher elasticity receiving the impact of the screen and being applied to the zone of lower elasticity, so as to ensure a gradual deceleration of the screen.
• the stopper is preferably disposed between the periphery of the screen and the axis of rotation thereof, being close to the percussion center of the screen, so as to attenuate the reaction on the pivots of the 'screen.
• Figure 1 shows schematically, in elevation, a switch device provided with an arc cut screen and a deformable screen stop according to the invention
• Figure 2 shows, on a larger scale, the detail A of Figure 1;
• Figure 3 is a sectional view along III-III of Figure 2;
• Figure 4 shows, on a larger scale, the crushing of the stop by the screen
• FIG. 5 is a partial section along the plane V-V of FIG. 4.
• the switching device 10 illustrated in FIG. 1 is a circuit breaker comprising a box 11 and, in this box, an interruptible electrical circuit which includes a magnetic trip device 12, as well as a fixed contact 13 and a movable contact 14.
• L device 10 which could also be a circuit breaker or a contactor-circuit breaker, controls an external circuit capable of being connected to terminals 15, 16. The current flows, for example, from terminal 15 to terminal 16 by the movable contact 14, the fixed contact 13 and the trip device 12 via the connections indicated in dashes.
• the trigger 12 acts on the movable contact 14 via a lock (not shown), while a button or lever 17 allows manual opening of the contacts or resetting.
• a thermal trigger can be provided to act on the lock.
• a cut-off screen 20 made of insulating material is rotatably mounted on pivots 19 of axis X-X in the housing 11 (see FIGS. 4 and 5).
• Such a screen is described in French patent 2,563,939 and it can be actuated directly or indirectly by the magnetic trip device 12 to interpose between the fixed contacts 13 and movable 14 in order to contribute to stretching, cooling and destabilizing the arc of break. In the present embodiment, it is a direct drive by a tail 21 of the plunger 22 of the trigger 12.
• the cut-off screen 20 normally occupies a rest position 20a (FIG. 1 and in dashed lines in FIG. 4) towards which it is returned by a torsion spring 23 and it can be propelled by the tail 21 of the magnetic trip device 12 towards a stop. elastically deformable 24.
• the screen 20 reaches the stop in a contact-making position 20b (FIG. 4) with a speed of the order of 20 m / s and an acceleration greater than 200g; it crushes the stop until it comes to position 20c (figure 4).
• the respective movements of the parts 21, 20 and 14 during an opening are indicated by the arrows f 1 , f 2 , f 3 in FIG. 4.
• the stop 24 consists of a relatively high elasticity zone formed by a thin annular partition 25 and a relatively low elasticity zone - or relatively rigid zone - formed by a solid stopper 26.
• the partition 25 is attached to the foot of the stopper 26 so as to flex and crash on it to compress it as shown in Figure 4.
• the areas 25, 26 could of course be arranged and arranged differently, to allow in all cases a gradual deceleration of the screen and a restitution to it of its percussion energy with a determined delay guaranteeing that the return of the screen under the combined effect of this energy and that of the return spring 23 will only take place once the arc is extinguished.
• the deformable stop 24 is preferably disposed between the periphery 27 of the screen 20 and the axis X-X near the center of percussion of the screen in order to attenuate the reaction on the pivots 19.
• the housing may consist of two mutually assemblable parts, the walls 11a, 11b of which are provided from the molding with respective elastically deformable stops 24a, 24b facing each other.
• the deformable stops cooperate with edges 28, 29 of the screen, substantially parallel to the walls 11a, 11b constituting a part of the front surface of the screen.

Landscapes

• Arc-Extinguishing Devices That Are Switches (AREA)
• Breakers (AREA)

Applications Claiming Priority (2)

Publications (2)

Family

ID=9333363

Family Applications (1)

Country Status (6)

Families Citing this family (7)

Family Cites Families (7)

• 1986
  • 1986-03-21 FR FR8604042A patent/FR2596196B1/fr not_active Expired
• 1987
  • 1987-03-23 WO PCT/FR1987/000088 patent/WO1987005745A1/fr active IP Right Grant
  • 1987-03-23 DE DE8787902102T patent/DE3774227D1/de not_active Expired - Lifetime
  • 1987-03-23 JP JP62501977A patent/JPS63502941A/ja active Pending
  • 1987-03-23 US US07/130,344 patent/US4849591A/en not_active Expired - Fee Related
  • 1987-03-23 EP EP87902102A patent/EP0261189B1/de not_active Expired - Lifetime

Non-Patent Citations (1)

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