Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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The invention relates to a rapid manual cloqing mechanism
of a current breaking device, notably a switch or circuit
- 5 Breaker, with a handle connected by a kinematic chain to
a contact armO
ckground of the invention
Miniature circuit breakers, in particular those for modular
electrical distribution installations, comprise a manual
spening and closing operating handle. ~he clo3ing oper-
ation cause~ a ~pring to be loaded ensuring rapid opening
of the contacts in the event oP a fault and assisting the
handle in the opening operation. When a slow clo~ing oper-
ation takes place or the handle i~ held in an intermediatepo~ition, -the contact pressure may be insufficient for the
current to flow properly and overheating of the contacts
may cause welding or erosion. To avoid this drawback, it
has already been proposed to insert in the transmission
mechanism between the handle and the contact arm an energy
storage spring which comes into action at the end of c109-
ing travel to bring about rapid closing of the contacts.
Prior art devices are complicated and interrupt the direct
linkage between handle and contact arm by systems of artic-
ulated leverq.
The object of the present invention i9 to provide an oper-
a-ting mechanism o~ a miniature circuit breaker which is e2-
~- tremely simpLe and able to bring about rapid clo~ing of the
; 3o contactsO
Surnmar~ of the invention
The clo3ing mechanism according to the present invention
comprises an abutmen-t which can be overrun located at a
prede-termined point of the trajectory o~ movement of one
of the switchgear closing mechanism elements, in ~uch a way
as -to irnpede said movement and constitute a han~lp point
requiring an increased force on the handle to overrun said
point which corresponds to a position of the contact arm
close to the position where the contacts come into contact
to bring about closing by the action of said increased
~orce as soon as said hangup point is overrun.
The presence of a hangup point on the closing travel of
the handle compels the operator to exert an increased act-
uating force on the handle in order to overrun this hangup
point~ ~his actuating force becomes fully available as soon
as the retaining abutment i~ overrun Nhen the han~lp point
is passed and is sufficient to cause rapid movement of the
contacts to the closing position. The hangup point corres-
ponds to a position of the con-tacts close to the closing
position and it is practically impossible for an operator
to move the handle beyond -the hangup point and to hold it
in an intermediate position between this hangu~ poin-t and
the closing position. ~he abutment which can be overrun is
advantageously formed by a flexible part which is deformed
by the ac-tion of the handle and is automatically cleared
after a predetermined deformationO Unlike prior art energy
storage me~hànisms, the loaded fle~ible par-t does not res-
tore the energy to the mechanism to bring about rapid clos-
ing~ the latter being brought about by operator action on
the handle. It is clear that the abutment or the flexible
part can be added to standard mechanisms without modifying
the latter to transform a circuit breaker and ensure rapid
closing of the contacts.
The abutment which can be overrun is inactive in the pivot-
ing direction of the handle corresponding to opening of the
contacts in order not to impede this pivoting of the handle~
either when actuated manually, or due to -the effect of a
return spring on circuit breaker tripping. ~he flexible
part is advantageously a fle~ible strip which can pivot
freely in the direction corresponding to opening of the
contacts~ whereas it co~es into abutment against a protrus-
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ion of the casing when the handle pi~ots in the oppo~itecontact closing directionO The flexible strip is held
pressed agai.nst the pro-trusion o~ the casing by mean~ of
a return spring.
Brief description of the drawin~
Other advantages and characteri~tics will become more
clearly apparent ~rom the following description o~ a
specific embodiment o~ the invention, by way of example
only, and represented by the accompanying dra~ngs, in
which :
- ~igure l is schematic cross-sectional view acros~ the
middle of a mechanism according to the invention~ repres-
ented in the contact open position ;
- figure 2 is a similar view to that of ~igure 1, showing
the mechanism in the contact clo~ed posi-tion ;
ZO - figures 3 -to 5 are partial views of figure 11 showing
the handle and clearable abutment respectively during clos-
ing movement before and after the hangup point is overrun,
and during opening movement of the contacts ;
- figure 6 illustrates the curve o~ the variation in the
torque required to pivo-t the handle during a clo~ing oper-
ation.
Descript on of the pre~erred embodiment
Figures l and 2 are views of a mechanism described in det-
ail in Can. Pat. Appln. No. 436,903 of Sept. 16,1Y~3, which wil`l
be advantageousLy referred to for further details. It is sufficient
to recall that the pivoting handle lO is pivotably moun-ted
on a stationary shaft 12, the body 14 o~ the han~lle having
a pin 16 operating a toggle joint 20 made up o~ ar-ticulated
rodq 18, 22. ~he rod 22 belongs to a rocker arm 24 pivot-
ably mounted on a stationary shaft 26 and having an exten-
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sion 28 bearing a pivot 30 on which a contact arm 32 ismounted. ~he movable contact 38 is mounted on one of -the
ends 34 of the arm 32 and cooperates with a fixed contact
40, whereas the opposite end cooperates with a locking
~butment 36 of a trip lever 44 pivotably mounted on a
pivot 46. A contact pressure spring 42 urges the movable
contact 38 into the closed po~ition. A catch 48, operated
by a magnetic or thermal tripping device 50 (not shown),
cooperates with the lever 44 to bring abou-t tripping of
the circuit breaker in the event of a fault. A spring 52
urges the contact arm into the contact opening position.
A mechanism of this kind, described in detail in -the above-
mentioned patent, is well-lcnown to specialis-ts, and it i~
pointless describing it in greater detail.
According to the present invention, the body 14 of the
handle lO has a protruberance or hump 54 which follows a
circular trajectory when handle lO pivots and comes into
20 contact during its movement with the end oE a strip 56
articulated on a fiæed pivot 58 secured to the casing 60.
A coil ~pring 62 urges the strip 56 into abutment against
a protrusion 64 of casing 60 which limits pivoting of -the
strip 56 in the -trigonometric direction in figure 1. Pivot-
25 ing in the oppo~ite direction takes place Ereely by over-
coming the ~orce of the return spring 62. ~he strip 56 is
~lexible to enable it to be deformed by the action o~ the
protruberance 54, a deforma-tion c~using on the one hand a
storage o~ energy, and on the other hand, the withdrawal
3o of the end of the fle~ible strip 56 from the trajectory OI
movement of the protruberance 54 which~ once it has over
run the strip 56, moves freely.
Operation of the device according to -the invention is des-
35 cribed below, referring more particularLy to figures 3 to
6:
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In the circuit breaker open position, represented in figure
1, the flexible strip 56 is held in abutment against the
protrusion 64 by the spring 62, the protruberance 54 being
a~ay from the strip 56. In the course o~ a closing oper-
ation of the switchgear by clockl,vise pivoting o~ the han-
dle 10, -the protruberance 54 comes up against the end of
the flexible strip 56 and causes bending of the latter
held in abutment against the protrusion 64 (fig. 3)~ Defor-
mation of the flexible strip 56 requires ~n increased torque
to operate handle 10, represented in figure 6 in -terms of
the pivoting angle cC of the handle 10. ~he position Cl
corresponds to the protruberance 54 engaging against the
strip 56, the position C2 corresponding to the strip 56
being overrun by the pro-truberance 54 ~fig.4). Overrunning
the strip 56 corresponding -to -the position ~c2 takes place
just before the con-tac-ts ~8, 40 come into contact corres-
ponding to the position oC3. ~rom the moment this coming
into contact occurs, an additional effort is necessary to
load the contact spring 42, which is expressed by an in-
crease in the torque C required to operate the handle 10In the course of the continuing pivo-ting movement of -the
handle 10, the spring 42 is loaded until the dead point
(P.M. in figure 6) of the toggle join-t constituted by the
rods 18, 22 is reached. 3eyond this dead point, the handle
is urged by the mechanism to the stable closed posi-tion.
As soon as the flexible s-trip ~6 has been passed, the lat-
ter reverts to its ini-tial position without the stored
energy being transmitted to the mechanism. It is clearly
apparent from figure 6 that the presence of the flexible
strip 56 imposes an increased effort to operate the handle
10 t'nroughout the deformation phase of the flexible strip
56, this increased effort enabling, once the fle~ible
strip 56 has been passed, -the contacts to be closed rapidly
absorbing without difficulty the compression ~orce of -the
contact spring 42.
In the course of a mamlal circuit breaker opening o~eration
3 55 ~
the protruberance 54 comes up against the end of the flex-
ible strip 56 making it pivot clock-,~ise against the return
spring 62 (fig.5). The opposing ~orce is virtually neglig~
ible and it is possible to admit that the s-trip 56 does
not exert any in~luence on the circuit breaker opening
operation.
.
It is clear that the invention is in no way limited to the
particular embodiment described, the ~le~ible strip 56
being able to cooperate with another element of the mech-
anism, notably of the contact arm 32 or of the toggle sys-
tem, that the opposing force can be generated by any other
flexible or stored energy system, and that movement o:f the
handle can talce place in a straigh-t line,
