Contact breaker with magnetic arc blowing

An electrical contact breaker has a stationary contact, and a movable contact. The movable contact is connected to a terminal by a flexible conductor. For blowing out the arc formed when the contacts separate under load, there is a blowing means including a winding traversed by the current, and pole pieces directing the magnetic field of the winding to the vicinity of the arc gap. The improvement is that the winding is constituted by at least part of the flexible conductor.

BACKGROUND OF THE INVENTION 
The invention relates to a contact breaker, for the interruption of 
electric currents, comprising a fixed contact cooperating with a movable 
contact coupled to a terminal by a flexible conductor, and a magnetic 
blowing means constituted by a winding which is traversed by the current 
of the contact breaker and of which the magnetic field is guided by pole 
pieces to the vicinity of the breaking zone. 
Such contact breakers are particularly used for the breaking of heavy 
currents, and hitherto the blowing winding was constituted by several 
turns of a heavy conductor placed adjacent to the fixed contact. 
The winding of the conductor becomes increasingly critical as its section 
became greater in order to be able to carry the heavy currents. In 
practice it is not possible to give the turns an internal diameter as 
small as is desirable, and there are large losses between the winding and 
the associated pole pieces. The mounting of the winding, generally of 
large dimensions, requires bulky mounting means which result in 
disadvantageous arrangement of the breaking chamber. There must also be 
added the cost of a flexible conductor. 
OBJECT OF THE INVENTION 
The object of the invention is to provide an improved construction which 
eliminates the inconveniences of the known devices. 
SUMMARY OF THE INVENTION 
According to the invention this result is achieved in that the winding is 
constructed with a flexible conductor which serves simultaneously to 
couple the movable contact, fast with an insulating contact carrier, to 
the corresponding terminal. 
Other features of the invention will be apparent from the following 
description with reference to the accompanying drawings.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
The contact breaker shown in FIG. 1 comprises a fixed contact 7 made fast 
with a first coupling terminal 8 of a casing. With the contact 7 there 
cooperates a movable contact 3 secured on a lever 9 capable of pivoting on 
a bearing surface 13 formed in a contact carrier of insulating material, 
the carrier being itself capable of pivoting about a fixed axis YY' fast 
to the casing 14, of which only a portion has been shown. 
The contact carrier has a boss 15 intended for coupling with the movable 
part of an electromagnet (not shown) or with that of any other driving 
member, for example a pneumatic ram, the direction of contact-closing 
operation of which is indicated by the arrow F. 
A pivotable bolt 12 engaged movably in the contact carrier 4 bears against 
one end of a helicoidal compression spring 11, the other end of which 
spring bears on a cross member 10 of the lever 9 in order to provide the 
contact pressure during closing. 
A conductive portion 17, fast with the movable contact 3, or with the lever 
9 which is metallic, or again which is disposed between these two elements 
in order to be held by a bolt 26, comprises at least one opening, such as 
16, receiving a first end 18 of a flexible braid 2, made of copper, 
forming a turn 20 the central axis XX' of which is placed above and in the 
vicinity of the movable contact when the latter is open. This axis is 
common to a cylindrical magnetic core 19 which is fast with magnetic 
flange plates of which one, 21, is shown in chain-dotted line and which 
extends as far as the arcing zone 22, the second flange plate 25 being 
visible in FIG. 2. 
The second end 23 of the braid 2 is made mechanically and electrically 
integral with a bracket 24 which is an extension of the second coupling 
terminal 5 as shown or which can be coupled thereto. 
This braid 2 thus fulfills simultaneously the functions of electrical 
connection of the movable contact and of the winding for the magnetic 
blowing of the arc. 
In FIG. 2 this first braid 2 is seen to be placed in parallel with a second 
braid 6 which is symmetrical with the former about the plane PP', which is 
perpendicular to the plane of the figure and which constitutes the plane 
of displacement of the movable contact during closing and opening.