Linear control apparatus for a circuit-breaker

Linear control apparatus for a circuit-breaker, the apparatus including a slidably-mounted tubular arm actuated by a solenoid, and a "disengagement" first slide which presses against the tubular arm, the first slide being subjected to a first spring assembly. The control end of the drive rod is coupled to the tubular arm via at least one projecting portion passing through a respective longitudinal slot provided along the tubular arm. The control apparatus includes an "engagement" second slide to which the drive rod is fixed via its projecting portion, the engagement second slide being subjected to an "engagement" second spring assembly which displaces it from the circuit-breaker disengaged position to the circuit-breaker engaged position under the action of second control means.

FIELD OF THE INVENTION 
The present invention relates to control apparatus for a circuit-breaker. 
More precisely, the present invention concerns linear control apparatus for 
engaging and disengaging a circuit-breaker that includes a drive rod 
provided with a control end, the apparatus itself including a 
slidably-mounted tubular arm which is actuated by a solenoid, which has 
the same longitudinal axis as the drive rod, and which is coupled to the 
drive rod whose control end is inside the tubular arm, and a 
"disengagement" first slide which presses against the tubular arm and 
through which the drive rod passes, the first slide being subjected to a 
"disengagement" first spring assembly which displaces it from the 
circuit-breaker engaged position to the circuit-breaker disengaged 
position under the action of first control means actuated on 
disengagement. 
BACKGROUND OF THE INVENTION 
In such known circuit-breaker control apparatus, disengagement is performed 
by means of the disengagement spring assembly which is constituted by a 
helical spring that is coaxial with the drive rod, with one of its ends 
pressed against a fixed portion, and with its other end pressed against 
the first slide, the spring being held compressed in the circuit-breaker 
disengaged position by the control means constituted by retractable 
slide-retaining means for retaining the slide. On disengagement, said 
slide-retaining means are retracted, and the released spring drives the 
slide and therefore the tubular arm, thereby driving the drive rod and 
opening the contacts of the circuit-breaker. On engagement, the drive is 
provided by the solenoid on its own, with the tubular arm driving the 
slide against the force of the spring which is re-compressed until it is 
latched by the retaining means, and also driving the drive rod to the 
engaged position in which the contacts are closed. 
That type of control suffers from the drawback that it is dangerous on 
engagement, because the drive for performing such engagement is provided 
by the solenoid on its own, and if a malfunction occurs in the solenoid, 
the contacts might not be closed, or, in particular, they might be closed 
abnormally. 
The present invention solves this problem by providing apparatus such that 
the control end of the drive rod is coupled to the tubular arm via at 
least one projecting portion fixed to the drive rod and passing through a 
respective longitudinal slot provided along the tubular arm, and such that 
the control apparatus includes an "engagement" second slide to which the 
drive rod is fixed via its projecting portion, the engagement second slide 
being subjected to an "engagement" second spring assembly which displaces 
it from the circuit-breaker disengaged position to the circuit-breaker 
engaged position under the action of second control means actuated on 
engagement. 
In a first variant embodiment of the first spring assembly, said first 
spring assembly is constituted by a helical spring which is coaxial with 
the drive rod, and which has one of its ends pressed against a first fixed 
portion and its other end pressed against the first slide, the first 
spring being held compressed in the circuit-breaker engaged position by 
the first control means constituted by retractable slide-retaining means 
for retaining the first slide. 
In a second variant embodiment of the first spring assembly, said first 
spring assembly is constituted by two telescopic arms which have their 
longitudinal axes lying in the same plane, each one of the facing ends of 
the arms being connected to the first slide via a respective pivoting 
link, and the other end of each arm being pivotally fixed to a respective 
fixed point, a spring surrounding the arm being compressed between the 
pivoting link and the fixed end, and the first control means are 
preferably constituted by a drive member for driving the first slide. 
In a first variant of the second spring assembly, said second spring 
assembly is constituted by a helical spring which is coaxial with the 
tubular arm, and which has one of its ends pressed against a second fixed 
portion and its other end pressed against the second slide to which the 
drive rod is fixed via its projecting portion, the second spring being 
held compressed in the circuit-breaker disengaged position by the second 
control means constituted by retractable slide-retaining means for 
retaining the second slide. 
In a second embodiment of the second spring assembly, said second spring 
assembly is constituted by two telescopic arms which have their 
longitudinal axes lying in the same plane, each one of the facing ends of 
the arms being connected to the second slide via a respective pivoting 
link, and the other end of each arm being pivotally fixed to a respective 
fixed point, a spring surrounding the arm being compressed between the 
pivoting link and the fixed end, and the second control means are 
preferably constituted by a drive member for driving the second slide.

MORE DETAILED DESCRIPTION 
In a first variant embodiment as shown in FIGS. 1A, 1B, and 1C, the linear 
control apparatus for engaging and disengaging a circuit-breaker that 
includes a drive rod 1 provided with a control end 2, itself includes: a 
slidably-mounted tubular arm 3 which is actuated by a solenoid 14, which 
has the same longitudinal axis as the drive rod 1, and which is coupled to 
the drive rod 1 whose control end 2 is inside the tubular arm 3; and a 
"disengagement" first slide 4 which presses against the tubular arm 3 and 
through which the drive rod 1 passes, the first slide 4 being subjected to 
a "disengagement" first spring assembly 5 which displaces it from the 
circuit-breaker engaged position to the circuit-breaker disengaged 
position under the action of first control means 6 actuated on 
disengagement. 
The first spring assembly 5 is constituted by a helical spring which is 
coaxial with the drive rod 1, and which has one of its ends pressed 
against a first fixed portion 12 and its other end pressed against the 
first slide 4, the first spring 5 being held compressed in the 
circuit-breaker engaged position by the first control means 6 constituted 
by retractable slide-retaining means for retaining the first slide 4. 
The slide-retaining means 6 are constituted by a latch member co-operating 
with a flange 15 formed on the first slide 4, which member is actuated by 
a disengagement coil 16. 
The control end 2 of the drive rod 1 is coupled to the tubular arm 3 via at 
least one projecting portion 7 fixed to the drive rod 1 and passing 
through a respective longitudinal slot 8 provided along the tubular arm 3. 
The control apparatus includes an "engagement" second slide 9 to which the 
drive rod 1 is fixed via its projecting portion 7, the engagement second 
slide being subjected to an "engagement" second spring assembly 10 which 
displaces it from the circuit-breaker disengaged position to the 
circuit-breaker engaged position under the action of second control means 
11 actuated on engagement. 
The second spring assembly 10 is constituted by a helical spring which is 
coaxial with the tubular arm 3, and which has one of its ends pressed 
against a second fixed portion 13 and its other end pressed against the 
second slide 9 to which the drive rod 1 is fixed via its projecting 
portion 7, the second spring 10 being held compressed in the 
circuit-breaker disengaged position by the second control means 11 
constituted by retractable slide-retaining means for retaining the second 
slide 9. 
The slide-retaining means 11 are constituted by a latch member co-operating 
with a flange 17 formed on the second slide 9, which member is actuated by 
an engagement coil 18. 
In the position shown in FIG. 1A, the apparatus is in the engaged position. 
The first slide 4 driven by the arm 3 actuated by the solenoid 14 and by 
the second slide 9 driven by spring 10 is retained by latch member 6. The 
released spring 10 drives the second slide 9 and therefore the end 2 of 
the drive rod 1 to the engaged position. 
On disengagement, as shown in FIG. 1B, the disengagement coil 16 is 
actuated and it releases spring 5 which drives the first slide 4 together 
with the arm 3 released by the solenoid 14 and together with the second 
slide 9, thereby driving the end 2 of the drive rod to the disengaged 
position. The flange 17 on the second slide 9 is then locked by latch 
member 11. 
Once this position has been reached, the arm 3 is driven by the solenoid 
14, as shown in FIG. 1C, thereby driving the first slide 4 while 
compressing spring 5, and slide 4 is locked via its flange 15 by latch 
member 6. The drive rod 1 is not displaced and it remains in the 
disengaged position coupled to the locked second slide 9 because of the 
presence of the slot 8. This operation may be performed within a very 
short length of time, i.e. about 0.3 seconds, corresponding to the 
standardized circuit-breaker isolation time. 
The apparatus is then in a position to be re-engaged quickly by releasing 
the flange 17 on the second slide 9 so as to return to the engaged 
position shown in FIG. 1A. 
The "disengagement" first spring 5 develops a force that is greater than 
the force developed by the "engagement" second spring 10, and the springs 
are therefore dimensioned accordingly. 
FIGS. 2A, 2B, and 2C show a second embodiment of the apparatus of the 
invention, in which the spring assemblies 5, 10 are constituted by 
snap-acting members that act suddenly relative to a over-center unbalanced 
position. 
The first spring assembly 5 is constituted by two telescopic arms 50, 50' 
which have their longitudinal axes lying in the same plane. Each one of 
the facing ends of the arms is connected to the first slide 4 via a 
respective clevis-type pivoting link 51, 51', and the other end of each 
arm is pivotally fixed to a respective fixed point 52, 52', a spring 53, 
53' surrounding the arm 50, 50' being compressed between the clevis 51, 
51' and the fixed end. 
The first control means 6 are constituted by a drive member for driving the 
first slide 4, which drive member is an arm 6 actuated by a disengagement 
coil 16. 
The second spring assembly 10 is constituted by two telescopic arms 100, 
100' which have their longitudinal axes lying in the same plane. Each one 
of the facing ends of the arms is connected to the second slide 9 via a 
respective clevis-type pivoting link 101, 101', and the other end of each 
arm is pivotally fixed to a respective fixed point 102, 102', a spring 
103, 103' surrounding the arm 100, 100' being compressed between the 
clevis 101, 101' and the fixed end. 
The second control means 11 are constituted by a drive member for driving 
the second slide 9, which drive member is an arm 11 actuated by an 
engagement coil 18. 
In the position shown in FIG. 2A, the apparatus is in the engaged position. 
The first slide 4 is driven by the arm 3 actuated by the solenoid 14. 
Spring assembly 10 drives the second slide 9 and therefore the end 2 of 
the drive rod 1 to the engaged position. In this position, a flange 17 
formed on the second slide 9 abuts against a fixed element (not shown). In 
this way, there is a gap between the slides 4 and 9, and there is also a 
gap between the projecting portion 7 and the end of the slot 8. 
Furthermore, the first spring assembly 5 is in a position that is very 
close to its over-center position corresponding to a vertically aligned 
position in which the arms 50 and 50' are in vertical alignment, as shown 
in FIG. 2A. 
On disengagement, as shown in FIG. 2B, the disengagement coil 16 is 
actuated and it drives out arm 6 which drives spring assembly 5 and arm 3 
released by the solenoid 14. This takes place easily over the above 
mentioned gaps, and once it has been driven in this way, spring assembly 5 
has gone beyond its over-center position and it in turn drives arm 3 and 
the second slide 9, thereby driving the end 2 of the drive rod 1 to the 
disengaged position. The flange 17 on the second slide 9 abuts against the 
arm 11 of the engagement coil 18. In this position, it is the second 
spring assembly 10 which is in a position that is very close to its 
over-center position corresponding to a vertically aligned position in 
which arms 100 and 100' are in vertical alignment, as shown in FIG. 2B. 
Once this position has been reached, arm 3 is driven by the solenoid 14, as 
shown in FIG. 2C, thereby driving the first slide 4 together with the 
first spring assembly 5 against the arm 6 of the disengagement coil 16. 
The drive rod 1 is not displaced and it remains in the disengaged position 
coupled to the locked second slide 9 because of the presence of the slot 
8. This operation may be performed within a very short length of time, 
i.e. about 0.3 seconds, corresponding to the standardized circuit-breaker 
isolation time. 
The apparatus is then in a position to be re-engaged quickly by the second 
slide 9 being driven by the arm 11 of the engagement coil 18 so as to 
return to the engaged position shown in FIG. 2A. 
The "disengagement" first spring assembly 5 develops a force that is 
greater than the force developed by the "engagement" second spring 
assembly 10, and the spring assemblies are therefore dimensioned 
accordingly.