Information
-
Patent Grant
-
6307455
-
Patent Number
6,307,455
-
Date Filed
Tuesday, October 10, 200024 years ago
-
Date Issued
Tuesday, October 23, 200123 years ago
-
Inventors
-
Original Assignees
-
Examiners
Agents
- Oblon, Spivak, McClelland, Maier & Neustadt, P.C.
-
CPC
-
US Classifications
Field of Search
US
- 335 6
- 335 21
- 335 22
- 335 24
- 335 25
- 335 26
- 335 27
- 335 35
- 335 36
- 335 38
-
International Classifications
-
Abstract
Circuit breaker mechanism comprising a manually controlled part 40a acted upon by a knob 42 and a part 40c with an electromagnetic overcurrent tripping device 41 and a trip spring 65. The parts 40b, 40c act on a common lever 43 through a connecting rod 62 and a control lever 66 respectively. The part 40b is coupled to a lever 64 onto which the spring 65 exerts a torque, and also applies an opening torque to lever 66.
Description
BACKGROUND OF THE INVENTION
This invention relates to a control mechanism for a circuit breaker comprising poles with separable contacts.
This type of mechanism usually includes a manual control part used to start and stop and reset, and a trip part comprising an electromagnetic tripping device, a pivoting latch-in lever, and a pivoting control lever with a pawl normally held in place by the latch and acted upon by a trip spring, the tripping device pivoting the latch-in lever and unlatching the control lever to open the contacts, in response to an overcurrent.
In a particular circuit breaker called “contactor-circuit breaker” or hereafter circuit interrupter, the mechanism must also include a part for switching the contacts using an electromagnet depending on whether or not the electromagnet coil is energized.
SUMMARY OF THE INVENTION
The purpose of this invention is to simplify such a circuit breaker mechanism by having some of its component parts perform several functions.
According to the invention, an oscillating lever is installed free to pivot on a hinge pin and is coupled with the manual control part, while the trip spring exerts an opening torque on the control lever through a first bearing point and a return torque on the oscillating lever through a second bearing point. The double-acting trip spring is preferably a compression spring, and the second spring bearing point is put into the On position slightly offset from the line between its first bearing point and the hinge pin of the oscillating lever, and when tripping takes place the offset forces the oscillating lever into an intermediate position between its On position and its Stop position.
The manual control part advantageously comprises a knob and a sliding connecting rod cooperating directly with the oscillating lever and coupled to a multipole contact actuator lever, the connecting rod and the knob being able to move into an On position, a Stop position and an intermediate trip position.
The sliding connecting rod may be used with a pivoting lock, this lock being able to lock the connecting rod in the On position and is provided with an arm coupled to a strip designed to move the auxiliary contacts, and transferring three positions (“On”, “Off” and “Tripped”) to the strip. The manual control part is coupled to a single sliding strip with three positions (On, Off and Tripped) to activate at least one signaling device.
BRIEF DESCRIPTION OF THE DRAWINGS
The following description relates to a non-limitative embodiment of the invention with reference to the attached drawings.
FIG. 1
is a diagram of a circuit breaker conform with the invention.
FIGS. 2
to
5
illustrate the circuit breaker in the “On” state, the “Off” state and the “Tripped” state and during resetting.
FIGS. 6A
to
6
D illustrate the positions of the knob in the states of the device shown in
FIGS. 2
to
5
.
FIG. 7
shows a perspective view of the manual control mechanism rod.
FIGS. 8 and 9
are diagrammatic views of the oscillating lever and the latch-in lever.
FIG. 10
is a diagrammatic view of the control lever.
FIG. 11
illustrates the lock on the manual control rod in perspective.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The circuit breaker shown in
FIG. 1
comprises several contact poles fitted with fixed contacts
10
and mobile contacts
11
associated with extinguishing chambers
12
. The fixed contacts
10
are connected by power conductors
13
,
14
to source power terminals
15
and load power terminals
16
placed in the equipment housing
17
or on terminal blocks fitted on the equipment. The contact poles are of the double break type and therefore the mobile contacts
12
are placed on a bridge
18
moved in the closing direction by the action of a spring
18
a
and in the opening direction by the action of a device driving a pusher
19
associated with each pole.
The casing
17
of the circuit breaker comprises a single block or a set of casings assembled to each other, forming a rear attachment face
17
a
to be connected to a support. It comprises an electromagnet
20
and an electronic protection device
30
, that is designed to act on the pushers
19
for the various poles to open and close the contacts.
In the case of an overload or overcurrent, the protection device
30
controls an electromagnetic tripping device
41
with intermittent action. The core of the electromagnetic trip
41
acts on a lever of a lock belonging to a contact control mechanism
40
through a pusher
41
a
; the pusher
41
a
has a lateral contact surface
41
b
that facilitates its return to its rest position and it is moved into its tripped position by a spring
41
c.
A manual control knob
42
that can be placed in an On position or an Off position operates with mechanism
40
to control switching of contacts
11
. Obviously, it would be possible to use two knobs, one On knob and one Off knob, for manual control. The control mechanism
40
includes a bistable automatic control part
40
a
controlled by the electromagnet
20
starting from an On or Off order transferred to its terminals, a manual control part
40
b
controlled directly by knob
42
and a trip part
40
c
controlled by the electromagnetic tripping device
41
and cooperating reciprocally with the manual control part
40
b.
Note that the three parts
40
a, b, c
of the mechanism
40
act on a common pivoting lever
43
. This is a multipole lever which is mounted to pivot about a fixed axis O
1
and has two arms
43
a,
43
b.
Arm
43
a
is coupled to mechanism
40
b
and arm
43
b
is acted upon by a lever not shown driven by electromagnet
20
through a lever not shown and by a control lever
66
that can be moved by the tripping device
41
. Arm
43
b
has one free end
44
that comes into contact with the top of the various polar pushers
19
to open the contacts when one of the parts
40
a,
40
b,
40
c
of the mechanism is acted upon.
The manual control part
40
b
of the mechanism
40
comprises a transfer system
61
that transforms the rotation movement of knob
42
(about axis O
3
) into a translation movement along a direction X
2
parallel to the displacement of the pushers
19
, and connecting rod
62
that moves along this same direction X
2
. In particular, the return system
61
includes a rotating finger
61
a
fitted on an axis O
4
providing mechanical coupling with the connecting rod.
The connecting rod
62
is shown in more detail in FIG.
9
. There is one position of the connecting rod for each position of the knob, shown in
FIGS. 6A
to
6
D, namely the “On” position (FIG.
6
A), the “Off” position (FIG.
6
B), the “Tripped” position (
FIG. 6C
) and the “Reset” position (FIG.
6
D). At its upper end located towards knob
42
, the connecting rod
62
is provided with an opening
62
a
into which the operating finger
61
a
of the return system
61
fits, and a recess
62
b
which extends along the X
2
direction and which is provided with straight slides
62
i
running along the X
2
direction and with notches
62
c
setback from these slides to cooperate with a pivoting elastic lock
63
.
The connecting rod
62
is fitted with arms
62
d
that fit together through a pin or tenons
62
e
provided with a slide or an oblong hole
64
a
of an oscillating lever
64
at their free end. At its lower end near the contacts, the connecting rod
62
comprises an opening
62
f
in which the end of the arm
43
a
of lever
43
fits to provide a bi-univocal link. Furthermore, the connecting rod is fitted with pins
62
g
that cooperate with slides
62
h
oriented along the X
2
direction to guide it.
The oscillating lever
64
can rotate about an axis O
5
and one end
65
a
of a helical compression spring
65
is fitted to it through a bearing axis O
6
. The oscillating lever
64
is also provided with an arm
64
b
located towards the contacts and an opposite arm
64
c
facing away from the contacts and towards the tripping device
41
; the arm
64
b
is terminated with a contact surface
64
d
designed to cooperate in bearing with a control lever
66
and arm
64
c
is designed to cooperate with the contact surface
41
b
of the tripping device
41
in order to reset it.
The compression spring
65
(see
FIG. 8
) is hinged at its other end
65
b
close to its contacts about an axis O
7
of a control lever
66
itself able to pivot around an axis O
8
. Axes O
1
, O
2
, O
4
, O
5
, O
7
and O
8
are fixed and parallel to each other, and are perpendicular to the plane of the drawing in
FIGS. 2
to
5
and to X
1
and X
2
, whereas the axes O
6
, O
7
of the ends of the spring move as a function of the positions of the oscillating lever
64
and the control lever
66
. As will be seen later, the spring
65
exerts a torque on lever
66
tending to trip it to open contacts and exerts a torque on lever
64
tending to trip it into the off or reset position.
The control lever
66
is acted upon by the part
40
c
of the mechanism and cooperates with part
40
b.
The lever
66
presses on the multipole lever
43
close to the free end
44
of the arm
43
b
of lever
43
, through the end of an arm or an angle
66
b
on which the spring bearing axis O
7
is located. The end
44
of the lever
43
has a different opening distance depending on whether it is acted upon by part
40
b
or
40
c
of the mechanism.
Lever
66
is fitted with a pawl
66
a
normally in contact with a pin or a hinge pin
67
a
of a latch
67
. The shape of the control lever
66
is generally polygonal, and particularly trapezoidal, and an arm
66
fitted with pawl
66
a
and an arm
66
d
acting as a stop for the contact surface
64
d
on the oscillating lever
64
are latched to this lever, at the end opposite to axes O
8
and O
7
.
The latch
67
is mounted free to pivot about on axis adjacent to and parallel to axis O
5
, or preferably about axis O
5
itself, and it is moved by the cross-head of the sliding core
41
a
of the electromagnetic tripping device
41
acting on an arm
67
b,
the core being oriented to slide along direction X
1
.
The elastic lock
63
(see
FIG. 11
) is installed free to pivot around an axis O
9
located close to one end of the connecting rod
62
located close to parts
40
b,
40
c
of the mechanism. The lock
63
passes through an elongated central housing
62
b
in the connecting rod.
It comprises a heel
63
a
that can engage in contact with the notches
62
c
in the housing
62
b
of the connecting rod, and comprises a contact surface
63
b
into which the end of the core
41
a
of the tripping device
41
is applied, and an arm
63
c
that extends approximately along the X
2
direction along the connecting rod. The arm
63
c
is fitted with a driving end
63
d
at its end near the contacts, that is engaged with a strip
70
free to move along the X
1
direction. The strip
70
can activate at least one signaling device
71
, for example with mechanical contacts, capable of switching off the power supply to the electromagnet coil
20
when the knob
42
is put into the “Off” position, and/or signaling the “On”, “Off” or “Tripped” state of the switch. There are three positions (“On”, “Off”, “Tripped”) of the strip
70
corresponding to the above three mentioned positions of the knob
42
and the connecting rod
62
, that may for example be transferred to it by the lock.
The lock is acted upon by a tension spring
63
e
, which is also latched to a fixed point
63
f
and exerts a return force in the clockwise direction. The elasticity of the lock is such that an elastic effect is obtained at the heel
63
a
level through an internal elastic effect, possibly combined with the effect of a tension spring
63
g,
as in the case shown. The tripping part
40
c
of the mechanism
40
thus comprises the latch-in lever
67
and the control lever
66
and it dialogs with the oscillating lever
64
, the spring
65
and the lock
63
of connecting rod
62
.
The circuit breaker described operates as follows:
On (see FIG.
2
): knob
42
is in the On position shown in FIG.
6
A and it is assumed that the electromagnet
20
is energized so that lever
43
remains relaxed. The connecting rod
62
is moved into the low position by finger
61
a
rotating in the clockwise direction, such that the multipole lever
43
is switched over in the anti-clockwise direction releasing contact holders
19
. The result is that the contacts
10
,
11
for each pole are closed with a contact pressure exerted by spring
18
a.
Lock
63
is engaged on the connecting rod through its heel
63
a.
The tripping part
40
c
is held set in the state indicated in FIG.
4
: the pusher
41
a
is retracted towards the right, the latch-in lever
67
is switched over in the clockwise direction and latched to the pawl
67
a
of the control lever
66
itself switched over in the anti-clockwise direction. Note that the oscillating lever
64
is moved in the anti-clockwise direction by the hinge pin
62
e
such that the latching axis O
6
of spring
65
is approximately along the line between the pivoting axis O
5
of lever
64
and the axis O
7
at which the spring is latched to the control lever
66
. The axis O
6
is slightly offset towards the left of line O
5
-O
7
to induce a clockwise rotation of the oscillating lever
64
during the trip takes place.
Off:
for manual control (see FIG.
3
), the knob
42
is put into the off position shown in FIG.
6
B. The finger
61
a
is then raised and, while the heel
63
a
of the lock
63
is released from the notches
62
c
of the connecting rod
62
due to the elasticity of the lock, the connecting rod can slide into an extreme high position (the position closest to the knob). The result is that the multipole lever
43
is switched over in the clockwise direction and that its end
44
is applied to the pushers
19
and moves them along the maximum travel distance, for example of the order of 5.5 mm, and it is applied to the pushers
19
such that the contacts open with a travel distance eb. This travel distance eb is sufficient to make the device capable of causing isolation. Note that the trip part
40
c
remains in the same state as in FIG.
4
.
for automatic control by the electromagnet (see FIG.
13
), the lever
51
pivots in the clockwise direction and the contacts are open with a travel distance of less than eb.
Trip (see FIG.
4
):
in response to an overcurrent signal transmitted to the electromagnet
41
, the pusher
41
a
moves towards the left and strikes the latch-in lever
67
that switches over in the anti-clockwise direction and releases pawl
67
a;
the control lever
66
moves in the clockwise direction acted upon by the compression spring
65
, the free end
65
a
of which initially remaining fixed; the control lever
66
is applied to the multipole lever
43
over a travel distance of the order of 4.5 mm, such that the pushers
19
are pushed back and the contacts open with a travel distance ec. Note that ec is less than eb.
Secondly, the pusher
41
a
of the tripping device
41
continues its travel distance and arm
67
b
of the latch-in lever
67
strikes the contact surface
63
b
of the lock
63
. This lock moves into an extreme anti-clockwise position showing that the trip has taken place, that it sends to the signaling strip
70
through driving end
63
d.
The oscillating lever
64
returns in the clockwise direction to an intermediate position between its on and off positions; this return is due to the torque transferred to it by the upper end
65
a
of spring
65
, as a result of the initial offset of O
6
from line O
5
-O
7
. The intermediate position of the lever
64
is defined when its arm
64
b
reaches a limit stop in contact with arm
66
b
of the control lever
66
, which itself stops in contact with a fixed limit stop
66
e;
the above mentioned position of the lever
64
defines an intermediate position of the connecting rod
62
controlled by hinge pin
62
e
through slide
64
a,
and consequently an intermediate position of the knob
42
. After the contacts
71
have been acted upon, the strip is pulled towards the left by the arm
63
c
of lock
63
that is itself returned by its tension spring
63
e.
Reset (see FIG.
5
):
the knob
42
is rotated to a position beyond the off position in order to reset the mechanism after a trip, in order to displace the connecting rod
62
to an extreme low position which rotates the oscillating lever
64
in the clockwise direction, and this lever through its arm
64
c
pushes the tripping device pusher into its rest position (at the right in the figures), and through its arm
64
b
releases the lever
66
slightly in the anti-clockwise direction. The latch-in lever
67
returns to its latched position under the effect of a return spring (not shown) and when knob
42
returns to the Off position, the pawl
66
a
latches on the latch
67
a
and the switch is reset.
Claims
- 1. Circuit breaker control mechanism comprising a manually controlled part (40b) used to put the switch into the On and off and Reset positions, and a trip part (40c) comprising an electromagnetic tripping device (41), a pivoting latch-in lever (67) and a pivoting control lever with a pawl (66) normally held in position by the latch and acted upon by a trip spring (65), the tripping device pivoting the latch-in lever and detaching the control lever to open the contacts, in response to an overcurrent characterized by the fact that:an oscillating lever (64) mounted free to pivot about an axis (O5) is coupled with the manually controlled part (40b), the trip spring (65) exerts an opening torque on the control lever (66) through a first bearing point (O7) and a return torque on the oscillating lever (64) through a second bearing point (O6).
- 2. Mechanism according to claim 1, characterized by the fact that the trip spring (65) is a compression spring, and the second bearing point (O6) of the spring (65) is put in the On position slightly offset from the line joining its first bearing point (O7) to the axis (O5) about which the oscillating lever (64) pivots, the offset moving the oscillating lever (64) into an intermediate position between its On position and its off position when a trip occurs.
- 3. Mechanism according to claim 1, characterized by the fact that the manual control part (40b) is fitted with a knob (42) and a sliding connecting rod (62) cooperating directly with the oscillating lever (64) and coupled to a multipole lever (43) to move the contacts, the connecting rod (62) and the knob (42) being able to move into an On position, an Off position and an intermediate trip position.
- 4. Mechanism according to claim 3, characterized by the fact that the sliding connecting rod (62) is associated with a pivoting lock (63), the pivoting lock being able to lock the connecting rod in the On position and being fitted with an arm (63c) coupled to a strip (70) designed to move the auxiliary contacts.
- 5. Mechanism according to claim 4, characterized by the fact that the pivoting lock (63) informs the strip (70) of the three positions (“On”, “Off”, and “Tripped” respectively).
- 6. Mechanism according to claim 5, characterized by the fact that the electromagnetic tripping device (41) initially trips the latch-in lever (67), and then puts the pivoting lock (63) into its tripped position.
- 7. Mechanism according to claim 1, characterized by the fact that the control lever (66) is fitted with a limit stop (66d) onto which the oscillating lever (64) is applied when the equipment is Tripped and/or off.
- 8. Mechanism according to claim 1, characterized by the fact that the manual control part (40b) is coupled to a single sliding strip (70) with three positions (On, Off and Tripped) to activate at least one signaling device (71).
Priority Claims (1)
Number |
Date |
Country |
Kind |
99 12793 |
Oct 1999 |
FR |
|
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Number |
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Date |
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Sep 1977 |
|
5252933 |
Kamino et al. |
Oct 1993 |
|
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