EP1036396B1

EP1036396B1 - Fuse disconnector

Info

Publication number: EP1036396B1
Application number: EP98904452A
Authority: EP
Inventors: Witold Stolarczyk; Wieslaw Antal; Zbigniew Zych; Edward Chwajta
Original assignee: Legrand Fael Sp zoo
Current assignee: Legrand Fael Sp zoo
Priority date: 1997-12-04
Filing date: 1998-02-25
Publication date: 2002-01-23
Anticipated expiration: 2018-02-25
Also published as: DE69803605T2; ATE212471T1; PL183078B1; DE69803605D1; PL323568A1; EP1036396A1; WO1999028936A1

Abstract

Fuse disconnector is characterized by the fact, that its moving contact is switched on by a lever operation which has a stiff tension member (31) with one arm seated in a rotary bearing (32) in traverse (4) and with the other arm co-operating with a part (30) in a trip lever (3) with a longitudinal axle situated on a radius attached in the rotation-point of a trip lever (3), while a blocking lever (5) is double-armed, seated in a bearing of an axle (15) which is fixed permanently in a disconnector's body (1) and its end (5a) co-operates with a notch (3a) of a trip lever (3), and the other end (5b) co-operates with a shaped side-surface of a limiter-insert (6), while insert's (6) inner diameter depends on the value of a rated current of a disconnector, and a pressure pad, (26) seated in a bearing (32) formed in insert made of a homogeneous material (6), is pressed down by a flat spring (13) to a terminal (22).

Description

The subject of the invention is a fuse disconnector intended to protect a wiring system from short-circuits and overcharging, easy to assemble that is the main protection and the main breaker as the protection of a meter and following units in the system.

DE-U-92 11 229 (corresponding to EP-A-0 584 587), on which the preamble of claim 1 is based, discloses a disconnector, which contains a fuse-socket, and a contact-system started by a hand-moved trip lever placed on a frontal surface of disconnector. The Disconnector has two current terminals: one for connecting a conductor supplying voltage from a network and the other for connecting an offtake of energy to a receiver. A current circuit in a disconnector linking two terminals consists of a contact-system and a fuse-element connected in series. Moving contacts are coupled by means of a stiff pusher with a trip lever whose hand-shifting from one operation position to another causes a change of circuit's state: closed or open: Shifting of moving contacts when closing as well when opening takes place with a speed dependent on speed of trip lever's shifting. In the whole range of angular shifting of a trip lever, the end of a pusher follows a recess in this lever. While switching on circuits with a low power factor or with significant powers it has an unfavourable effect on disconnector's life as well as on a run of transient currents in a circuit. Disconnection of a current circuit enables safe removing of a fuse element from disconnector's socket because it stays in a voltageless and currentless state.

In on-position of a trip lever, a replacement of a fuse-element is not possible because a fuse-head is covered by lever's arm.

Shift of a trip lever into an on-position, when a fuse-head is totally or partly screwed out, is impossible because of a blocking mechanism started by a moving contact of a fuse-element. Under the force of a push-spring the contact shifts when the fuse-head is being screwed out. Correct functioning of a blocking mechanism is dependent on the precision of elements that a mechanism is composed of, because most of them are not fixed to a housing and they are movable. Apart from a switching-on function, fuse disconnectors serve also as a protection against the results of short-circuit and overcharging. This function is performed by a built-in fuse-element. Disconnectors are protected by additional metal limiter-rings and thus installation of a fuse-element with a rated current greater than a disconnector's rated current is impossible, otherwise it could be dangerous for a protected circuit, and it could arise, for example ,from an operator's error. Every rated current needs a different size of a ring.

EP 0 242 664 also discloses an electric connector, hand-operated, with a double-arm trip lever seated in a rotary bearing of a housing. Shifting of this lever between an opening position and a closing position causes closing and opening out of a contact bridge. A contact bridge in this connector is shifted by means of a toggle formed by a trip lever's arm linked by a rotary-slidable joint with a slider. A tail end of a slider presses a contact bridge. A slider has got a latch-nose between its ends. After shifting a trip lever to a closing position a nose shifts behind a mesh with a latch-cog, stationary towards a housing. After crossing toggle's straightening position towards closing of contacts, a slider can move freely in a trip lever. Pressure of a spring placed under a contact bridge causes that a slider, together with a contact bridge is percussively shifted to contacts' closing position. So intermittent switching on is obtained, no matter how quickly a trip lever is shifted by the operator.

The purpose of this invention is designing a simple fuse disconnector where contacts of a current circuit close dynamically, no matter how quickly a trip lever is shifted, and protection against switching a lever on when a fuse-head is screwed out is simple, not demanding a special precision in construction of many elements. Besides this, its task is to simlify the protection system against installation of a fuse-element with rated current greater than rated current of a disconnector.

The essence of the invention lies in the fact that a moving contact is switched on by hand-operation which has a stiff tension member with one arm seated in rotary bearing in traverse and with the other arm co-operating with a port in a trip lever with a longitudinal axle situated on a radius attached in the rotation-point of a trip lever. A blocking lever is doublearmed, seated in a bearing of an axle which is fixed permanently in a disconnector's body and its one end co-operates with a notch of a trip lever and the other end co-operates with a shaped side-surface of a limiter-insert. Insert's inner diameter's size (made of a homogeneous material) depends on the value of a rated current of a disconnector. An additional disconnection of a current circuit is achieved by a pressure pad, seated in a limiter-insert. The pad is pressed down by a flat spring to a terminal.

The port in a trip lever is a hole in the shape of an arc resting on an angle of approximate 90, and the radius of the arc is attached in a rotation axis of a trip lever and lies on the opposite side of a trip lever's arm.

Resistance in the body reduces the tension member's pressure in the port on a trip lever. A blocking lever is pressed down to a trip lever by a spring.

A pressure pad is seated in a slidable bearing situated in a limiter-insert. The end of the pad, forming a contact with a terminal, is bent at an angle corresponding to an angle of terminal's bend.

One of the advantageous results of this invention is a lesser wear of contact tips in a disconnector and a better transient currents' run when switching on a circuit, and also a simplicity and low costs of blocking mechanism and limiter-insert as well as a reliability of additional contact gap's system.

A fuse disconnector is presented in a drawing, where figure 1 shows a disconnector in on-position, figure 2 a disconnector in open-state, figure 3 shows the action of disconnector's blocking mechanism.

The housing of disconnector with a fuse-socket is made of plastics and consists of two parts: body 1 and cover 2. The two parts are connected with each other by rivets 27.

In the middle part of disconnector's housing there is a fuse-socket with a fuse-element 10 which is fixed by a cylindrical head of the fuse 8.

In a trip lever 3 there is a sight-hole 18 which enables to look into a round window 28 protected by a pane 9 and it is used to control the state of a fuse-element 10. A fuse-element 10 is surrounded by a round thread 25 connected with a fuse-head 8. A free part of a round thread 25 is connected with a holder 24 (permanently seated in the body 1 of disconnector24) of a fuse element10, and it enables an electric run from a holder 24 through a thread 25 to a fuse-element 10.

A holder 24 is linked with a left terminal 21 through a moving contact 23. From the other side, an electric run takes place from a fuse-element 10 on - seated in a slidable bearing 33 a pressure pad 26 to a right terminal 22, and a required connecting power is obtained by a flat spring's pressure 13.

A current circuit in on-state closes from a left connecting terminal 19 through a left terminal 21 on a moving contact 23, and then from a contact on a holder 24 of a fuse-element 10, from where-through a round thread 25 on a fuse-head 8, a fuse-element 10, its pressure pad 26 and a right terminal 22 to a right connecting terminal 20.

A movement of a trip lever 3 around an axle 11 to an open-position causes opening of a moving contact 23 and disconnecting of a circuit.

A hole 30 situated in a trip lever 3 enables the transfer of a drive on a tension member 31. A stiff tension member 31 has one arm seated in a rotary bearing 32 in traverse 4 and the other arm co-operating with a port 30 in trip lever 3. A rotary movement of a lever 3 around an axle 11 causes shifting of a tension member 31 which overcomes spring's force 14 and shifts a traverse 4 together with a moving contact 23 and thus a disconnection of circuit between a terminal 21 and a holder 24 takes place. A resistance 29 situated in a body 1 enables keeping a trip lever 3 in an open-state. A spring 15 protects against clearances between a tension member 31 and a trip lever 3 as contact tips get worn out in a disconnector.

Additionally, screwing a fuse-head 8 out causes shifting of a limiter -insert 6 together with a pressure pad 26 under the operation of a pressure spring 17 in its upper position, what forms an additional break in a contact between a pressure pad 26 and a terminal 22.

A blocking mechanism of a disconnector works in an off-state; when a fuse-element is missing 10 or when it is not turned tight, the disconnector cannot work. While screwing a fuse-head out 8 a limiter-insert 6 is shifted under the operation of a spring 17 and blocking is released. Under the force of a blocking spring16 it turns around an axle 12 and the trip lever 3 is blocked by its end 5a and the notch of the lever 3a.

After the fuse-head 8 is screwed in together with fuse-element 10 the limiter-insert 6 is shifted at the same time to its bottom position. In the course of shifting the insert's 6 prong 6a operates the end 5b of blocking lever 5 and after reaching a specified contact -force between the pressure pad of insert 26 and terminal 22 there occurs the release of blocking and possibility of reinforcing the disconnector.

The disconnector has bistable latches 7 which enable easy assembly on the rail.

Claims

A fuse disconnector comprising a fuse socket (6, 25), a double-break contact system, placed within the disconnector (1) disconnecting a current line and hand-driven by a trip lever (3) coupled to a tension member (31), a blocking mechanism (3a, 5a) for said lever, a pressure pad (6) for said fuse element placed in a current line, which is arranged under a fuse element (10) and additionally disconnects a current circuit when said fuse element (10) is removed, a moving contact (23) coupled to a stiff tension member (31) with one arm seated in a rotary bearing (32) in traverse (4) and with the other arm cooperating with a port (30) in said trip lever (3) with a longitudinal axle situated on a radius attached in the rotation-point of a trip lever (3), a blocking lever (5), which is seated in a bearing of an axle, which is fixed permanently in a disconnector's body (1) and whose one end cooperates with a notch (3a) of said trip lever (3), wherein the inner diameter of an insert (6) depends on the value of a rated current of said disconnector, whereas a pressure pad (26) seated in a bearing (32) formed as an insert is made of a homogeneous material (6) and is pressed down by a flat spring (13) to a terminal (22), characterized in that said blocking lever (5) is double-armed and seated in a bearing of an axle (12), which is fixed permanently in a disconnector's body (1), one end cooperating with a notch (3a) of said trip lever (3) and the other end cooperating with a shaped side surface of said limiter insert (6), and in that said pressure pad (26) is seated in a bearing (32) formed as an insert and made of a homogeneous material, wherein said pressure pad (26) is pressed down by flat spring (13) to a terminal (22).
A fuse disconnector according to claim 1, characterized in that the port (30) of said trip lever (3) is a hole in the shape of an arc resting with an angle of approximately 90°, the radius of the arc being attached in a rotation axis of said trip lever (3) and lying on the opposite side of said trip lever's arm.
A fuse disconnector according to claim 1, characterized in that a resistance (29) in the body (1) reduces the pressure of an arm of said tension member (31) in the port on said trip lever (3).
A fuse disconnector according to claim 1, characterized in that said blocking lever (5) is pressed down to said trip lever (3) by means of a spring (16).
A fuse disconnector according to claim 1, characterized in that said pressure pad (26) is seated in a slidable bearing (32) situated in a limiter insert (6), wherein an end of the pad, forming a contact with a terminal (22), is bent at an angle corresponding to an angle of the terminal's bend (22).