Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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ELECTRICAL SWITCHING APPARATUS HAVING A CRADLE WITH
COMBINED PIVOT AND OVER-TOGGLE REVERSING PIN
BACKGROUND OF THE INVENTION
Field of the Invention
The present invention relates to an electrical switching apparatus operating
mechanism and, more specifically to an electrical switching apparatus
operating
mechanism opening assembly having a cradle assembly with a pivot shaft that
acts as a
kicker for a toggle assembly.
Background Information
Electrical switching apparatus, typically, include a housing, at least one bus
assembly having a pair of contacts, a trip device, and an operating mechanism.
The
housing assembly is structured to insulate and enclose the other components.
The at
least one pair of contacts include a fixed contact and a movable contact and
typically
include multiple pairs of fixed and movable contacts. Each contact is coupled
to, and in
electrical communication with, a conductive bus that is further coupled to,
and in
electrical communication with, a line or a load. A trip device is structured
to detect an
over-current condition and to actuate the operating mechanism. An operating
mechanism is structured to both open the contacts, either manually or
following
actuation by the trip device, and close the contacts.
That is, the operating mechanism includes both a closing assembly and an
opening assembly, which may have common elements, that are structured to move
the
movable contact between a first, open position, wherein the contacts are
separated, and
a second, closed position. wherein the contacts are coupled and in electrical
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communication. The operating mechanism includes a rotatable pole shaft that is
coupled to the movable contact and structured to move each movable contact
between
the closed position and the open position. Elements of both the closing
assembly and
the opening assembly are coupled to the pole shaft so as to effect the closing
and
opening of the contacts.
In the prior art, an electrical switching apparatus operating mechanism
closing
assembly typically had a stored energy device, such as an closing spring, and
at least
one link coupled to the pole shaft. The at least one link, typically, included
two links
that acted cooperatively as a toggle assembly. When the contacts were open,
the
toggle assembly was in a first, collapsed configuration and, conversely, when
the
contacts were closed, the toggle assembly was, typically, in a second, in-line
position
or in a slightly over-toggle configuration. The toggle assembly typically
moved
through a third configuration, a reset configuration, while the contacts were
open and
which was a configuration during the resetting of the operating mechanism
prior to
closing the contacts. The opening spring biased the pole shaft to collapse the
toggle
assembly. The opening spring and toggle assembly were maintained in the
second,
in-line position by the trip device.
The force required to close the contacts was, and is, typically greater than
what a human may apply and, as such, the operating mechanism typically
included a
mechanical closing assembly to close the contacts. The closing assembly,
typically,
included at least one stored energy device, such as a spring, and/or a motor.
Closing
springs typically were about 2 inches in diameter and about 5 to 6 inches in
length.
These springs were structured to apply a force of about 1000 pounds. A common
configuration included a motor that compressed one or more springs in the
closing
assembly. That is, the closing springs were coupled to a cam roller that
engaged a
cam coupled to the motor. As the motor rotated the cam, the closing springs
were
compressed or charged.
The toggle assembly also included a cam roller, typically at the toggle joint.
The closing assembly further included one or more cams disposed on a common
cam
shaft with the closing spring cam. Alternatively, depending upon the
configuration of
the cam, both the closing spring cam roller and the toggle assembly cam roller
could
engage the same cam. When the closing springs were released, the closing
spring
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cam roller applied force to the associated cam and caused"the cam shaft to
rotate. That
is, the cam roller "operatively engaged" the cam. Rotation of the cam shaft
would also
cause the cam associated with the toggle assembly cam roller to rotate. As the
cam
associated with the toggle assembly cam roller rotated, the cam caused the
toggle
assembly cam roller, and therefore the toggle assembly, to be moved into
selected
positions and or configurations. More specifically, the toggle assembly was
moved so
as to rotate the pole shaft into a position wherein the contacts were closed.
Thus, the
stored energy from the closing springs was transferred via the cams, cam
shaft, toggle
assembly, and pole shaft to the contacts. Alternatively, as set forth in U.S.
Patent
Application Serial No. 11/693,198, filed March 29, 2007, a closing assembly
may also
utilize a ram assembly to act upon the toggle assembly. That is, as opposed to
a cam
moving the toggle assembly into the second, over-toggle position, a linearly
traveling
ram acts upon the toggle assembly at the toggle joint.
1 he electrical switching apparatus operating mechanism opening assembly is
structured to open the contacts by allowing the pole shaft to rotate. rhat is,
a trip
device included an over-current sensor, a latch assembly and may have included
one
or more additional links that were coupled to the toggle assembly.
Alternately, the
latch assembly was directly coupled to the toggle assembly. When an over-
current
situation occurred, the latch assembly was released allowing the opening
spring to
cause the toggle assembly to collapse. When the toggle assembly collapsed, the
toggle assembly link coupled to the pole shaft caused the pole shaft to rotate
and
thereby move the movable contacts into the open position. The latch assembly
could
also be actuated manually if desired.
l'he electrical switching apparatus operating mechanism opening assembly is
responsive to the release of the latch assembly and is structured to move the
toggle
assembly into the first, collapsed configuration. Typically, the latch
assembly
included a latch plate that was structured to rotate or pivot within the
housing
assembly. The latch plate included a latch edge that selectively engaged a D-
shaft.
When the D-shaft was in a first position, the D-shaft allowed the latch plate
to pivot.
When the D-shaft was in a second configuration, the latch plate latch edge
engaged
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the D-shaft and the latch plate could not rotate. The D-shaft was controlled
by the trip
device or by a manual input.
One or more links extended between the latch plate and the toggle assembly.
When the latch plate was held in place by the D-shaft, the motion of the
toggle
assembly is controlled by the rotation of the pole shaft and the closing
assembly.
When the latch plate is free to pivot, the latch plate, via the links, caused
the toggle
assembly to move. Thus, when the trip device, or a manual input, caused the D-
shaft
to rotate, the latch plate was free to pivot which in turn caused the toggle
assembly to
move from the second, over-toggle configuration to the first, collapsed
configuration
thereby allowing the contacts to separate. To reset the operating mechanism
opening -
assembly prior to the closing of the contacts by the closing assembly, the
toggle
assembly typically moved into a reset configuration. In this configuration the
contacts are open, but the D-shaft is reset and the latch plate latch edge re-
engages the
D-shaft. Thus, the latch plate is no longer free to rotate and the motion of
the toggle
assembly is controlled by the pole shaft and the closing assembly as set forth
above.
The operating mechanism opening assembly typically included a stop/kicker
pin. The stop/kicker pin was typically disposed in one of two locations,
either on the
link between the latch plate and the toggle assembly or fixed to the housing
assembly.
The stop/kicker pin initially stops the motion of the toggle assembly during
closing.
That is, the stop/kicker pin, acting in the stop pin capacity, was positioned
so that
when the closing assembly moved the toggle assembly through the toggle, the
stop/kicker pin arrested the motion of the toggle assembly in the second, over-
toggle
configuration. Typically, without the stop/kicker pin, the toggle assembly
would
collapse in a reverse direction. When the latch plate was released, the motion
of the
latch plate would cause the link between the latch plate and the toggle
assembly to
move toward the toggle assembly or, of the kicker pin was fixed, caused the
toggle
assembly to move toward the kicker pin. As the stop/kicker pin was contacting
the
toggle assembly and holding the toggle assembly in the second, over-toggle
configuration, the relative motion of the stop/kicker pin toward the toggle
assembly
caused the toggle assembly to pass back through the in-line position and, once
the
toggle assembly was through the toggle, the toggle assembly could collapse.
That is,
the stop/kicker pin caused the toggle assembly to move into the first,
collapsed
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configuration. Typically, there was some delay in the relative motion of the
kicker
pin and the toggle assembly because the stop/kicker pin was typically spaced
from the
pivot point of the associated link or the toggle assembly. That is, as the
assembly that
moved would initially move with a slow angular velocity about a pivot point
that is
distant from the kicker pin. Thus, the time between a release of the latch
plate and the
collapse of the toggle assembly was extended. This is a disadvantage as the
contacts
are not separated until the toggle is substantially collapsed.
In this configuration, the operating mechanism opening assembly and closing
assembly are disposed adjacent to each other. The closeness of the operating
mechanism opening assembly and closing assembly can create interference
problems
that must be addressed. For example, after the closing assembly moves the
toggle
assembly into the second, over-toggle configuration, the closing assembly
closing
device, e.g. the cam or ram as set forth above, is still disposed immediately
adjacent
to the toggle assembly. Under normal operating conditions, the closing
assembly
closing device is simply reset, thereby moving the closing assembly closing
device
away from the toggle assembly. If, however, an over-current condition occurs
immediately after the closing of the contacts, the closing assembly closing
device and
the toggle assembly must be separated so that the toggle assembly may
collapse.
Present configurations of the operating mechanism typically cause the closing
assembly closing device to be moved out of the way or allow the toggle
assembly
links to be separated. Both of these solutions have disadvantages. An assembly
structured to move the closing assembly closing device away from the toggle
assembly increases charging difficulty. An assembly structured to separate the
toggle
links, and subsequently recouple the toggle links adds complexity to the
opening
assembly.
There is, therefore, a need for an electrical switching apparatus operating
mechanism opening assembly wherein the kicker pin and the associated pivot
point
correspond to each other.
There is a further need for an electrical switching apparatus operating
mechanism opening assembly wherein the toggle assembly is moved away from the
closing assembly closing device rather than having the toggle assembly
separate or
having the closing assembly closing device move away from the toggle assembly.
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SUMMARY OF THE INVENTION
These needs, and others, are met by the present invention which provides for
an electrical switching apparatus operating mechanism opening assembly wherein
the
toggle assembly stop/kicker pin has been separated into a kicker pin and a
stop pin.
By separating the functions of the stop/kicker pin into separate pins, the
kicker pin
may now be located at the pivot point of the associated link. Further, the
kicker pin
and the stop pin are now disposed upon a cradle as opposed to an elongated
link. The
cradle has a faster initial rotation than the links of the prior art. The
cradle further
supports one of the toggle assembly links. Thus, rotation of the cradle causes
the
toggle assembly to move. The operating mechanism opening assembly is
configured
so that, when the associated latch assembly latch plate is released, the
cradle rotates so
that the toggle assembly is moved away from the closing assembly closing
device.
Thus, as the kicker pin is both the pivot point and the rotation of the cradle
is faster,
there is a shorter time between the release of the latch plate and the
collapse of the
toggle assembly.
Further, with these improvements, there is a further need for a device that
positions the cradle with respect to the latch plate and that prevents the
cradle from
over-rotating relative to the latch plate. That is, a device that limits the
motion of the
cradle relative to the latch plate so that the motion of the cradle is
controlled during
opening and closing of the contacts. This need is met by a latch plate link
having a
rotation stopping assembly. That is, the latch plate assembly includes an over-
rotation
pin and the latch plate link has a longitudinal extension that is structured
to engage the
over-rotation pin. Thus, as the cradle moves relative to the latch plate, the
latch plate
link is also in motion. When the latch plate link longitudinal extension
engages the
over-rotation pin, the movement of the cradle relative to the latch plate is
limited.
Thus, the motion of the cradle is controlled during opening and closing of the
contacts.
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BRIEF DESCRIPTION OF THE DRAWINGS
A full understanding of the invention can be gained from the following
description of the preferred embodiments when read in conjunction with the
accompanying drawings in which:
Figure 1 is an isometric view of an electrical switching apparatus with a
front
cover removed.
Figure 2 is an isometric view of the opening assembly with a side plate
removed for clarity.
Figure 3 is a schematic side view of the opening assembly when the contacts
are closed.
Figure 4 is a schematic side view of the opening assembly during opening
when the kicker pin initially engages the toggle assembly.
Figure 5 is a schematic side view of the opening assembly when the contacts
are open, the toggle assembly is in the first, collapsed configuration, and
the ram
assembly is discharged.
Figure 6 is a schematic side view of the opening assembly when the contacts
are open, the toggle assembly is in the first, collapsed configuration, and
the ram
assembly is charged.
Figure 7 is a schematic side view of the opening assembly when the contacts
are open, the toggle assembly is in the reset configuration, and the ram
assembly is
charged.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
As used herein, "coupled" means a link between two or more elements,
whether direct or indirect, so long as a link occurs.
As used herein, "directly coupled" means that two elements are directly in
contact with each other.
As used herein, "fixedly coupled" or "fixed" means that two compone7ts so
coupled move as one.
As used herein, "operatively engage" when used in relation to a component
that is directly coupled to a cam means that a force is being applied by that
component
to the cam sufficient to cause the cam to rotate.
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As used herein, a "pivot point" is a coupling between two or more members
that allows the members to pivot relative to each other. A pivot point may be,
but is
not limited to, an opening on each member and a separate rod, wherein the rod
extends through the openings, or, a rod on a first element and an opening on a
second
element wherein the first element rod extends through the second element
opening.
As used herein, links or members that are "pivotally coupled" to each other
are
coupled at a "pivot point."
As used herein, with reference to the kicker pin acting upon the toggle
assembly, and more specifically the kicker pin "causing" the toggle assembly
to
collapse, the word "cause" is defined broadly to include accelerating a
collapse. That
is, a toggle assembly, especially a toggle assembly that is held in the in-
line
configuration, may begin to collapse without contacting a kicker pin. Such a
collapse,
however, is slow and contact with a kicker pin substantially increases the
speed of the
collapse.
As shown in Figures 1, an electrical switching apparatus 10 includes a housing
assembly 12 defining an enclosed space 14. In Figure 1, the front cover of the
housing assembly 12 is not shown, but it is well known in the art. The
electrical
switching apparatus 10 further includes a conductor assembly 20 (shown
schematically) having at least one line terminal 22, at least one line
conductor 24, at
least one pair of separable contacts 26, at least one load conductor 28 and at
least one
load terminal 30. The at least one pair of separable contacts 26 include a
fixed
contact 32 and a movable contact 34. The movable contact 34 is structured to
move
between a first, open position, wherein the contacts 32, 34 are separated, and
a
second, closed position, wherein the contacts 32, 34 contact each other and
are in
electrical communication. The electrical switching apparatus 10 further
includes a
trip device 40 and an operating mechanism 50. The operating mechanism 50,
which
is discussed in more detail below, is generally structured to move the at
least one pair
of separable contacts 26 between the first, open position and the second,
closed
position. The trip device 40 is structured to detect an over-current condition
and,
upon detecting such a condition, to actuate the operating mechanism 50 to open
the at
least one pair of separable contacts 26.
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The electrical switching apparatus 10 also includes at least two, and
typically a
plurality, of side plates 27. The side plates 27 are disposed within the
housing
assembly 12 in a generally parallel orientation. The side plates 27 include a
plurality
of openings 29 to which other components may be attached or through which
other
components may extend. The openings 29 on two adjacent side plates 27 are
typically
aligned. While side plates 27 are the preferred embodiment, it is understood
that the
housing assembly 12 may also be adapted to include the required openings
and/or
attachment points thereby, effectively, incorporating the side plates 27 into
the
housini.t assembly 12 (not shown).
An electrical switching apparatus 10 may have one or more poles, that is, one
or more pairs of separable contacts 26 each having associated conductors and
terminals. As shown in the figures, the housing assembly 12 includes three
chambers
13A, 13B, 13C each enclosing a pair of separable contacts 26 with each being a
pole
for the electrical switching apparatus 10. A three-pole configuration, or a
four-pole
configuration having a neutral pole, is well known in the art. The operating
mechanism 50 is structured to control all the pairs of separable contacts 26
within the
electrical switching apparatus 10. Thus, it is understood selected elements of
the
operating mechanism 50, such as, but not limited to, the pole shaft 70
(discussed
below) span all three chambers I3A, 1313, 13C and engage each pair of
separable
contacts 26. The following discussion, however, shall not specifically address
each
specific pair of separable contacts 26.
As shown in Figure 2, the operating mechanism 50 includes an opening
assembly 52, structured to move the at least one pair of separable contacts 26
from the
second, closed position to the first, open position, and a closing assembly
54, structured
to move the at least one pair of separable contacts 26 from the first, open
position to
the second closed position. The opening assembly 52 and the closing assembly
54 both
utilize common components of the operating mechanism 50. The operation of the
closing assembly 54 is set forth in detail in U.S. Patent Application No.
11/693,198.
It is noted that the closing assembly 54 includes a ram 60 structured to
engage the
toggle joint 94, discussed below, and move the toggle assembly 80 from a reset
position to the closed position. Thus, in this embodiment the ram 60 is a link
driving
device 61. It is further noted
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that the ram 60 when it is in the discharged position is disposed adjacent to
the toggle
assembly 80 and acts as an obstacle to collapse 62 for the toggle assembly 80.
The opening assembly 52 includes a pole shaft 70, a toggle assembly 80, a
cradle assembly 120, and may contain latching assembly 140 having a latch
plate
assembly 150 and a latch plate link 170. It is noted that the latching
assembly 140 may
also be considered to be part of the trip device 40. The pole shaft 70 is an
elongated
shaft body 72 rotatably coupled to the housing assembly 12 and/or side plates
27. The
pole shaft 70 includes a plurality of mounting points 74 disposed on mounting
blocks
76 extending from the pole shaft body 72. As shown schematically in Figure 1,
the
pole shall 70 is coupled to the movable contact 34. The pole shaft 70 is
structured to
move between a first position, wherein the movable contact 34 is in its first,
open
position, and a second position, wherein the movable contact 34 is in its
second,
closed position. As set forth in US Patent 7,646,270, one or more closing
springs bias
the pole shaft 70 to rotate in the direction indicated by the arrow on Figure
3.
It is noted that, as shown in Figure 2, a single component, e.g. a first link
82 in
the toggle assembly 80 may include two, or more, members 82A, 82B with similar
shapes which are held in a spaced relationship and which move in concert. The
use of
multiple, separate members 82A, 82B may be used, for example, to provide added
strength to the link 82 or where space considerations do not allow for a
single thick
member 82A, 82B. Because these link members 82A, 82B perform the same
function,
have a similar shape, and move in concert, the following discussion will
simply
identify the link 82 by a single reference number as is shown in the side
views of
Figures 4-7. It is understood that the description of such a component applies
to each
member 82A, 82B of that component. It is further noted that such components
typically
rotate within a single plane. Thus, it is understood that where components are
shown to
overlap in Figures 4-7, those components are in different planes. It is
further
understood that components that extend perpendicular to the planes of the
various
components may contact more than one component. As used herein with reference
to
the opening assembly 52, the word "lateral" preceding an element
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indicates that such an element extends across the planes of two or more other
elements.
As shown in Figures 3-7, the toggle assembly 80 includes a first link 82 and a
second link 84 which are each generally flat, elongated bodies. The second
link 84
body is also curved as set forth below. The first and second links 82, 84 each
have a
first, outer end 86, 88 (respectively) and a second, inner end 90, 92
(respectively). A
pivot point is disposed at each of the first and second links first, outer
ends 86, 88 and
second, inner ends 90, 92. The first link 82 and the second link 84 are
pivotally
coupled together at the first link second, inner end 90 and the second link
second,
inner end 92 by a toggle joint 94. In this configuration, the first and second
links 82,
84 form a toggle joint 94. The toggle joint 94 may include a toggle roller 98.
That is,
the toggle joint 94 may include a pin 100 extending generally perpendicular to
the
plane of each link 82, 84. The pin 100 may also define an axle for the toggle
roller 98
which is, essentially, a wheel. The toggle roller 98 has a diameter of
sufficient size to
extend past the edges of the first and second links 82, 84.
The cradle assembly 120 includes an elongated body 122, a lateral pivot shaft
124, and a lateral stop pin 126. The cradle assembly body 122 has a first link
pivot
point 128. The cradle assembly body 122 is coupled to the cradle assembly
lateral
pivot shaft 124. The cradle assembly lateral pivot shaft 124 is disposed
between, and
rotatably coupled to the hosing assembly side plates 27. Thus, the cradle
assembly
body 122 may pivot about a fixed axis which is the cradle assembly lateral
pivot shaft
124. The lateral stop pin 126 is disposed generally between the cradle
assembly
lateral pivot shaft 124 and the first link pivot point 128. The cradle
assembly body
122 preferably includes an offset portion 130 having a latch plate link pivot
point 132.
The latch plate assembly 150 includes a body 152 and a lateral pivot shaft
154.
The latch plate assembly body 152 has a latch edge 153, a latch plate link
pivot point
156, and a lateral over rotation pin 158. The latch plate assembly body 152 is
coupled
to the latch plate assembly lateral pivot shaft 154. The latch plate assembly
lateral
pivot shaft 154 is disposed between, and rotatably coupled to the hosing
assembly
side plates 27. Thus, the latch plate assembly body 152 may pivot about a
fixed axis
which is the latch plate assembly lateral pivot shaft 154. The lateral over
rotation pin
158 is disposed, generally, between the latch plate assembly lateral pivot
shaft 154
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and the latch plate assembly body latch plate link pivot point 156. The latch
plate
assembly body latch edge 153 is structured to engage a 1)-shaft 160 or similar
device
that is part of the operating mechanism 50. Details of the D-shaft 160 and its
operation are set forth in U.S. Patent Application Serial No. 11/737,219. For
the
purpose of this application it is noted that the D-shaft 160 is structured to
selectively
rotate between a first position and a second position.
The latch plate link 170 has an elongated body 172 with a first pivot point
174, a
second pivot point 176 and a longitudinal extension 178. The longitudinal
extension 178
extends generally longitudinally outwardly beyond the latch plate link body
first pivot point
174. The longitudinal extension 178 is structured to engage the latch plate
assembly over
rotation pin 158.
The opening assembly 52 is assembled as follows. It is noted that the pole
shaft
70, the cradle assembly lateral pivot shaft 124 and the latch plate assembly
lateral pivot
shaft 154 are the three components that are rotatably coupled to the housing
assembly
side plates 27 and, as such, these three shafts 70, 124, 154 are the pivot
points that do
not move relative to the housing assembly 12. The pole shaft 70, as noted
above, is
rotatably coupled to the housing assembly side plates 27. The second link 84
is coupled
to the pole shall 70 and, more specifically, the second link first, outer end
88 is
pivotally coupled to a pole shaft mounting points 74. As the pole shaft
mounting points
74 are offset from the pole shaft 70 axis, rotation of the pole shaft 70
causes the second
link first, outer end 88 to move through an arc. As noted above, the first
link 82 and the
second link 84 are pivotally coupled to each other at the toggle joint 94. The
first link
82 is coupled to the cradle assembly body 122. That is, the first link, first
outer end 86
is pivotally coupled to the cradle assembly body first link pivot point 128.
As the
cradle assembly body first link pivot point 128 is spaced from the cradle
assembly
lateral pivot shaft 124. as the cradle assembly body 122 pivots, the cradle
assembly
body first link pivot point 128 also moves through an arc. It is noted that,
as shown on
Figure 2, a pin 1 may extend through multiple members 82A, 82B and extend to
the
side plate 27. As this pin 1 must move through an arc, the side plate opening
29
associated therewith is an arcuate opening.
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The latch plate link second pivot point 176 is pivotally coupled to the cradle
assembly body latch plate link pivot point 132. The latch plate link first
pivot point
174 is pivotally coupled to the latch plate assembly body latch plate link
pivot point
156. The latch plate link longitudinal extension 178 extends adjacent to, and
is
structured to engage, the lateral over rotation pin 158.
The toggle assembly 80 is structured to move between a first, collapsed
configuration (Fig. 5), a reset configuration (Fig. 7), and a second, slightly
over-
toggle configuration (Fig. 3). In the over-toggle configuration, the toggle
assembly
80 is typically between about 5 degrees and 15 degrees past toggle and,
preferably
about 10 degrees past toggle. In the first, collapsed configuration, the first
and
second link outer ends 86, 88 are generally closer together than when the
toggle
assembly 80 is in the second, over-toggle configuration. In the reset
configuration,
the first and second link outer ends 86, 88 are much closer together causing
the toggle
joint 94 to be offset toward the ram 60 as shown in Figure 7. The cradle
assembly
body 122 and the latch plate assembly body 152 are each structured to move
between
a first position and a second position as set forth below.
The opening assembly 52 operates as follows. As shown in Figure 3, the
opening assembly 52 and the ram 60 are in their respective positions that
immediately
follow a discharge of the closing assembly 54 as set forth in U.S. Patent
Application
No. 11/693,198. That is, the pole shaft 70 is in the second position, meaning
that the
contacts 26 are closed, and the toggle assembly 80 is in the second, over-
toggle
configuration. The cradle assembly body 122 is also in a second position
wherein the
lateral stop pin 126 is contacting the toggle assembly first link 82 adjacent
to the
toggle joint 94. The lateral stop pin 126 is the object that prevents the
toggle
assembly 80 from moving too far over-toggle. It is further noted that the
cradle
assembly lateral pivot shaft 124 is adjacent to, but not contacting the second
link 84.
The latch plate assembly body 152 is also in its second position wherein the
latch
plate assembly body latch edge 153 engages the D-shaft 160. D-shaft 160 is in
its
second position wherein the D-shaft 160 extends into the path of travel of the
latch
plate assembly body 152. When the latch plate assembly body 152 contacts the D-
shaft 160, the latch plate assembly body 152 cannot move into the first
position. The
bias of the closing springs on the pole shaft 70 further biases, via the
various linkages
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disclosed herein, the latch plate assembly body 152 to the first position.
Thus, it is the
latch plate assembly body 152 contact with the D-shaft 160 that prevents the
opening
assembly 52 from moving and allowing the contacts 26 to open.
The latch plate link 170 extends between the latch plate assembly body 152
and the cradle assembly body 122. It is noted that the latch plate link
longitudinal
extension 178 engages the latch plate assembly over rotation pin 158 in the
reset
position, described below. Further, the latch plate assembly lateral pivot
shaft 154,
the latch plate link first pivot point 174, and the latch plate link second
pivot point
176 are disposed generally along a line. This is desirable as the contact load
is
minimized. The "contact load" is the force applied by the latch plate assembly
body
152 on the D-shaft 160. A minimal load is desirable as the actual contact area
between the latch plate assembly body 152 and the D-shaft 160 is small.
Further a
minimal load reduces the force required to release the D-shaft 160. It is
further noted
that, as shown, the ram 60 is in a forward, discharged position.
When an opening of the contacts 26 is initiated, for example, but not limited
to, following an over-current condition trip or a manual opening, the D-shaft
160
rotates to a second position wherein the D-shaft 160 does not extend into the
path of
travel of the latch plate assembly body 152. As shown in Figure 4, the latch
plate
assembly body latch edge 153 has moved past the D-shaft 160 and the latch
plate
assembly body 152 is pivoting clockwise as shown in the figures. As the latch
plate
assembly body 152 pivots, the latch plate link first pivot point 174 is moved
clockwise as well. This motion is transferred via the latch plate link 170 to
the cradle
assembly body 122 causing the cradle assembly body 122 to move counter-
clockwise
about the cradle assembly lateral pivot shaft 124. At this point in time, the
pole shaft
70 is not rotating, or rotating minimally, as the toggle assembly 80 is still
in the over-
toggle configuration. Thus, as the cradle assembly body 122 moves counter-
clockwise about the cradle assembly lateral pivot shaft 124, the toggle
assembly 80,
and more specifically the toggle assembly first link 82 which is coupled to
the cradle
assembly body first link pivot point 128, also moves counter-clockwise.
The counter-clockwise motion of the toggle assembly 80 has two specific
results. First, as the cradle assembly lateral pivot shaft 124 does not change
position,
the cradle assembly lateral pivot shaft 124 being the axis of rotation for the
cradle
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assembly body 122, the toggle assembly 80 is moved toward the cradle assembly
lateral pivot shaft 124. As shown in Figure 4, the cradle assembly lateral
pivot shaft
124 contacts the toggle assembly second link 84 adjacent to the toggle joint
94. As
the toggle assembly 80 continues to move toward the cradle assembly lateral
pivot
shaft 124, the cradle assembly lateral pivot shaft 124 causes the toggle
assembly 80 to
move back through the in-line position from the over-toggle configuration.
Thus, the
cradle assembly lateral pivot shaft 124 acts as a kicker pin 200.
Further, as the toggle assembly first link 82 continues to move counter-
clockwise with the cradle assembly body first link pivot point 128, the toggle
assembly 80 and the toggle joint 94 are being pulled away from the ram 60.
Thus,
when the toggle assembly 80 passes through the toggle point and the toggle
assembly
80 collapses into the first, collapsed configuration, as shown in Figure 5,
the toggle
assembly 80 and the toggle joint 94 are moved away from the ram 60 which is an
obstacle to collapse 62 for the toggle assembly 80. Further, the second link
84 is a
curved body 85 structured to curve around the obstacle to collapse 62 when the
toggle
assembly 80 is in the first configuration. In this manner, the toggle assembly
80 may
be collapsed without having to move the obstacle to collapse 62 which, as
noted
above, is typically the closing assembly 54 closing device.
Once the toggle assembly 80 passes through the toggle point and the toggle
assembly 80 is collapsing into the first, collapsed configuration, the bias of
the closing
springs on the pole shaft 70 cause the pole shaft 70 to move into its first
position
wherein the contacts 26 are open. Further, in this configuration the cradle
assembly
body 122 and the latch plate assembly body 152 are each in their respective
first
positions.
Prior to closing the contacts 26 using the closing assembly 54, the opening
assembly 52 must be reset. Initially, the closing assembly 54 closing device,
which as
shown is the ram 60, must be moved. Typically, this is accomplished by
charging the
closing assembly 54 and is shown in Figure 6. Then, as shown in Figure 7, the
latch
plate assembly body 152 is returned to its second position by rotating counter-
clockwise about the latch plate assembly lateral pivot shaft 154. As before,
the motion
of the latch plate assembly body 152 is transferred via the latch plate link
170 to the
cradle assembly body 122 causing the cradle assembly body 122 to move
clockwise
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16
about the cradle assembly lateral pivot shaft 124. As the pole shaft 70 is
maintained
in its position by the bias of the opening springs, the motion of the cradle
assembly
body 122 causes the toggle assembly 80 to move into the reset configuration.
As
noted above, when the toggle assembly 80 is in the reset configuration, the
toggle
joint 94 is offset toward the ram 60. Further, as part of the reset operation,
the D-shaft
160 is returned to its second position wherein the D-shaft 160 extends into
the path of
travel of the latch plate assembly body 152. It is also noted that, in this
configuration,
the latch plate link longitudinal extension 178 is structured to engage the
latch plate
assembly body over rotation pin 158 and prevent over-rotation of the cradle
assembly
body 122 relative to the latch plate assembly body 152 and stops the motion of
the
latch plate assembly body 152 relative to the cradle assembly body 122.
Finally, from
this configuration, the contacts 26 are closed, and the opening assembly 52 is
returned
to the configuration shown in Figure 3, by actuating the closing assembly 54
as
detailed in U.S. Patent Application No. 11/693,198.
While specific embodiments of the invention have been described in detail, it
will be appreciated by those skilled in the art that various modifications and
alternatives to those details could be developed in light of the overall
teachings of the
disclosure. Accordingly, the particular arrangements disclosed are meant to be
illustrative only and not limiting as to the scope of invention which is to be
given the
full breadth of the claims appended and any and all equivalents thereof.
