GB2230384A

GB2230384A - Electromagnetic switch with lockable forced operation

Info

Publication number: GB2230384A
Application number: GB9005489A
Authority: GB
Inventors: Patrick Larcher; Christophe Michelot; Christian Pichard
Original assignee: La Telemecanique Electrique SA; Telemecanique SA
Current assignee: Telemecanique SA
Priority date: 1989-04-13
Filing date: 1990-03-12
Publication date: 1990-10-17
Anticipated expiration: 2010-03-12
Also published as: CH682603A5; ATA79890A; DE4010142A1; IT9019937A0; FR2646012B1; DE4010142C2; GB2230384B; GB9005489D0; ES2021509A6; IT1242220B; IT9019937A1; FR2646012A1; AT404411B

Description

ELECTROMAGNETIC SWITCHING APPARATUS WITH LOCKED FORCED OPERATION.

The present invention relates to an electromagnetic switching apparatus comprising several poles and, for acting on these poles in automatic operation and respectively in forced operation, an electromagnet and a manual control button, as well as a kinematic chain for actuating the mobile contacts which uses, in both cases, the same driving piece.

Such known apparatus, for example contactors and other automatic switching apparatus, comprise in a case:

- several poles, each pole comprising at least one fixed contact and one mobile contact which are separable, - an electromagnet having a coil and an armature controlled by a spring, - the armature being coupled to a driving piece capable of acting on the contacts for opening and closing them as a function of the power supply to the coil, - a manual control button disposed close to a front face of the case and urged by a return spring, - the button cooperating with the armature or the driving piece via retention elements and being able to assume a position of automatic operation and a position of forced operation, in which it releases and, respectively, holds the armature or the driving piece.

When the manual control button is placed in its position of forced operation, the return spring of the armature contributes to holding the armature-driving piece coupling In the operating position and simultaneously causes a slight separation of the armature with respect to the fixed magnetic circuit. The result is that the power supply to the coil causes the armature to be again applied on the fixed magnetic circuit; the manual control button is thus released and comes back to its position of automatic operation under the effect of its return spring.

The object of the invention is in particular to provide, with freedom of choice and in a simple way in an electromagnetic switching apparatus of the described type, return to automatic operation or the continuation of forced operation, when an automatic "operation" command occurs during a manually controlled forced operation situation.

Another object of the invention is to make such a choice possible using mean's which are compact and cannot be actuated in an untimely way.

According to the invention, with the manual control button is associated a bolt which is accessible from outside the case and movable between a first position and a second position so that in its first position it allows the free movement of the button from the position of forced operation to the position of automatic operation and in its second position causes locking of the button in the position of forced operation.

The bolt may be placed at the side of the manual control button or be combined therewith. It may be movable by pivoting, rotation or translation, being mounted either on the button, or on the front f ace of the case, without however substantially projecting therefrom.

It may be advantageously formed by a slider movable in translation in a direction perpendicular to the direction of movement of the manual control button. The slider is mounted on a structure of the case or else is combined with the button; in the latter case, it is for example housed in a transverse opening of the button and has an imprint accessible to a tool which is inserted through a window formed in the button.

One embodiment of the switching apparatus according to the invention will be described hereafter, by way of non limitative example, with reference to the accompanying drawings. In these drawings:

Figure 1 shows schematically a sectional view in r, elevation of a contactor in accordance with the invention; Figures 2 to 4 show a front view of the case of the contactor, the manual control button and its locking slider occupying different positions; Figures 5 and 6 show on a larger scale, in section through planes V-V and W-W of figures 3 and 4, the button and the slider; Figure 7 is an enlarged view of the button-slider assembly shown in figure 1; Figures 8 to 10 show variants of embodiment of the bolt.

The electromagnetic contactor illustrated in the figures is a double pole contactor, but it may also have three or four poles. It comprises a case 10 with a f ront f ace 11 at the level of which is situated the tactile portion of a manual control button 12 having three positions, as well as a rear face 13 with means for clipping on a standardized support. The button may be placed in three positions: automatic or normal operation (AUTO), forced operation (I) and stop (0), respectively in the centre, at the right and left in figure 1, or else in the centre, at the top and at the bottom in f igures 2 to 4.

In case 10 is housed an electromagnet 14 which has a coil 15, a fixed magnetic circuit 16 and a mobile armature 17, the latter being located on the front side of the case. The armature 17 is urged by a return spring 18, whereas button 12 is urged from its position of forced operation to its position of automatic operation by a return spring 19.

Armature 17 is coupled to a driving piece 20 here formed by a flat link connected to a contact-holder 21 or applicable on a pivoting lever 22 itself connected to the contact-holder and urged towards a rest position by a return spring 23. The contact-holder comprises, for each power pole, a contact bridge 24 with two mobile contacts 0 each associated with a f ixed contact so as to be able to make or break a current path between two power terminals such as 1, 2. The contacts illustrated are of the closing type but may of course be of the opening type. They could 5 also be of simple cut-off type.

Coil 15 of the electromagnet is supplied with power when a current path passing through two control terminals Al, A2 is closed. This current path may be interrupted either by an external command or by button 12 in its stop position by means of a switch, not shown.

The manual control button 12 is formed by a plate 30 (see figure 7) housed under the front face 11 of the case substantially parallel to the latter and movable in a direction D1. Towards the front the plate has a projecting portion 31, at the level of face 11 or slightly projecting therefrom, for operation by a finger of the operator; towards the rear the plate has retention elements 32. These elements comprise a ramp and a bearing and possibly retention surf ace and they cooperate with complementary elements 33 provided either on a cover fixed to the armature or on an appropriate part of the driving piece 20. The retention elements may of course be formed and arranged differently.

A bolt, formed by a slider 35, is combined with button 12. The slider is housed in a transverse opening 36 of the button so as to move in a direction D2 perpendicular to D1. In the retracted position (figures 2, 3 and 5) the slider allows the free movement of the button from its position I to its position AUTO and in the extended position (figures 4 and 6) locks the button In its position I. In its extended position, slider 35 penetrates into a housing 37 formed in the case and the button remains locked by application of the slider against a retention face 37a of the housing. The latter Is a recess in a window 38 provided in the front face 11 for movement of the projecting portion 31 of the button.

1 1 - Slider 35 has an imprint 40 accessible by a tool (see figure 6) via a window 39 in the projecting part 31, as well as guide and retention elements 41 in the button. Thus, the button-slider assembly does not substantially project from the front face 11 and untimely actuation of the slider is avoided.

In the variant shown in f igure 8, slider 35a is an element associated with the projecting portion 31a of button 12a and is movable under a slide of this portion.

In figure 9 a bolt has been shown with pivoting cam 35b disposed on or in the projecting portion 31b of button 12b.

In f igure 10 is illustrated the case of a pivoting bolt 35c disposed so as to pivot on the case and having a flat which cooperates with a slit of appropriate shape 42 of button 12c.

It will be readily understood that bolt 35 may be mounted either on or in the button 12 for locking against a fixed element of case 10, on or in the front face 11 of the case for locking against a stop element of button 12.

The contactor according to the invention operates in the following way.

With the manual control button 12 in the AUTO position (figures 1 and 2), the armature 17 remains in the top position (figure 1) under the effect of spring 18 when the coil is not supplied with power; the same goes for the driving piece 20 and the contact-holder piece so that the contacts are open. As soon as the coil is supplied with power, armature 17 pivots in an anticlockwise direction (figure 1), the driving piece 20 moves down with the contact-holder; the contacts are closed and springs 18 and 23 are compressed.

When button 12 is placed in the position I with the coil not supplied with power and when slider 35 remains retracted (figures 3 and 5), elements 32, 33 are brought i 2 into action and force armature 17 and piece 20 downwards (figure 1) for closing the contacts; the armature remains slightly separated from the fixed magnetic circuit and the button remains held in the forced operation condition under the effect of springs 18, 23 with possibly slight retention. As soon as the coil is supplied with power, the armature 17 moves slightly down and releases button 12 which comes back to the AUTO position under the effect of spring 19.

When button 12 is placed in position I, causing slider 35 (figures 4 and 6) to project, the button remains held as before in the forced operation condition. When the coil is supplied with power, button 12 remains held in position I since slider 35 remains applied on face 37a.

The electromagnetic switching apparatus according to the invention may be formed by any automatic switching apparatus having a manual control allowing the choice between automatic operation and forced operation.

Claims

1. Electromagnetic switching apparatus comprising in a case:

- several poles, each pole comprising at least one f ixed contact and one mobile contact which are separable, - an electromagnet (14) having a coil and an armature (17) controlled by a spring, - the armature being coupled to a driving piece (20) 10 capable of acting on the contacts for opening and closing them as a function of the power supply to the coil, - a manual control button (12) disposed close to a front face (11) of the case (10), movable parallel to this front face and urged by a return spring, - the button cooperating with the armature or the driving piece via retention elements and being able to assume a position of automatic operation and a position of forced operation, in which it releases and, respectively, holds the armature or the driving piece, characterized by the fact that:

- with the manual control button (12) is associated a bolt (35) which is accessible from outside the case and movable between a first position and a second position so that, - in the f irst position the bolt (35) allows the free 25 movement of the button (12) from its position of forced operation to its position of automatic operation, - in the second positi on the bolt causes locking of the button in its position of forced operation.

2. Apparatus according to claim 1, characterized in that the manual control button (12) and the bolt (35) do not substantially project from the front face (11) of the case (10).

3. Apparatus according to claim 1 or 2, characterized in that the manual control button (12) moves In translation in a direction (D1) and the bolt (35) is a slider movable in a direction (D2) perpendicular to (D1).

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4. Apparatus according to one of claims 1 to 3, characterized in that the bolt (35) is mounted on or in the manual control button (12) and is applicable in its second position against a wall of a housing (37) formed in 5 the front face (11) of the case (10).

5. Apparatus according to one of claims 1 to 4, characterized in that the bolt (35) is housed in a transverse opening (36) of the button and comprises an imprint (40) accessible by a tool.

6. Apparatus according to claim 5, characterized in that the imprint (40) of the bolt (35) is accessible via a window (39) formed in a portion (31) of the manual control button (12) which is projecting but does not protrude from the front face (11) of the case.

7. Apparatus according to one of claims 1 to 3, characterized in that the bolt (35) is mounted in the front f ace (11) of the case for locking, in its second position, a stop element belonging to the button (12).

8.Electromagnetic switching apparatus substantially as described herein with reference to the accompanying drawings.

1 PubIlahea 1990atThePatentOffice.Stqite Ilouse.8671 H4h Holbo.-.n.lo.ndon W01E 4TP. ParLher oopies maybe obienafrom The Patent Office. Wet S ranah, St Mary Cray. Orpington, Kent BR5 3RD. Printed by Multiplex tacbidques ltd. St Mary Cray. Kent. Con. 1187