U.S. patent number 3,674,962 [Application Number 05/161,824] was granted by the patent office on 1972-07-04 for means for a retaining a circuit breaker handle in on position while the circuit breaker contact arms are latched in off position.
This patent grant is currently assigned to Square D Company. Invention is credited to Jerry E. Kroeger.
United States Patent |
3,674,962 |
Kroeger |
July 4, 1972 |
MEANS FOR A RETAINING A CIRCUIT BREAKER HANDLE IN ON POSITION WHILE
THE CIRCUIT BREAKER CONTACT ARMS ARE LATCHED IN OFF POSITION
Abstract
The circuit breaker has an enclosure with a cover. An exterior
operating handle is pivotally mounted on the cover for swinging in
a path alongside the outer face of the cover to and from ON and OFF
positions, selectively. A latching detent carried by the handle is
movable relative thereto toward and away from the cover and is
biased away from the cover by a spring. The cover carries an
abutment positioned in said path. When the handle is swung along
the path while the detent is in the retracted position, the detent
can pass the abutment. The abutment is close to the ON position of
the handle and can engage the detent when the handle is moved
slightly from ON toward OFF position while the detent is in
extended position. The force of the biasing spring is such that
frictional resistance of the engaged surfaces of the detent and
abutment can overcome the biasing force of the detent spring and
thereby hold the detent member in extended position and thereby the
handle in ON position, so long as a predetermined minimum applied
force is applied to the handle in a direction to bias the handle in
the OFF direction. The spring can retract the detent when the
applied force becomes less than said predetermined minimum. The
applied force is applied by toggle springs of the operating
mechanism of the circuit breaker which springs have been
preconditioned, by the movement of the handle to ON position, while
the circuit breaker contact arms are latched in OFF position, for
moving the contact arms of the circuit breaker to ON position when
the arms are released.
Inventors: |
Kroeger; Jerry E. (Mount
Vernon, IA) |
Assignee: |
Square D Company (Park Ridge,
IL)
|
Family
ID: |
22582905 |
Appl.
No.: |
05/161,824 |
Filed: |
July 12, 1971 |
Current U.S.
Class: |
200/321; 70/212;
200/318; 200/332 |
Current CPC
Class: |
H01H
9/282 (20130101); Y10T 70/5779 (20150401) |
Current International
Class: |
H01H
9/28 (20060101); H01H 9/20 (20060101); H01h
003/06 () |
Field of
Search: |
;200/5A,169R,169C,172A
;70/203,212 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Jones; H. O.
Claims
Having thus described my invention, I claim:
1. An electric circuit breaker including a handle member;
a supporting member supporting the handle member for movement along
a predetermined path, extending alongside one face of the
supporting member, to and from ON and OFF positions,
respectively;
contact carriers;
operating mechanism for the carriers including springs which, while
the carriers are latched in OFF position while the handle is in ON
position, bias the handle toward OFF position with a predetermined
force;
a latching detent element mounted on one of the members for
movement transversely of said path relative to said one of the
members toward and away from the other of said members to extended
and retracted positions, respectively;
spring means biasing the detent element to retracted position and
normally holding the detent element in retracted position;
an abutment element connected to the other of said members and
positioned so that the detent element, while in extended position,
is in alignment in a direction along said path with the abutment
element, and said elements have complementary abutment surfaces
which, while the detent element is extended, can be engaged when
the handle member is moved along said path to a predetermined
position;
said abutment element being positioned to clear the detent element
while the detent element is in said retracted position during
movement of the handle member along its said path;
characterized in that:
the one of said elements on the supporting member is positioned
along said path close to the ON position of the handle member and
has its abutment surface facing in a direction along said path
toward the ON position and, in the extended position of the detent
element, faces the abutment surface of the other element and is
aligned therewith endwise of the path;
the strength of the detent biasing spring is such that (a) the
frictional resistance of said abutment surfaces to movement of the
detent element by the spring to retracted position while the
surfaces are held in engagement by said predetermined biasing force
applied to the handle member and biasing it toward OFF position,
can overcome the biasing force of the detent biasing spring and
thereby hold the detent element in extended position and the handle
member in ON position so long as said predetermined biasing force
is applied, and (b) the detent biasing spring can overcome said
frictional resistance and retract the detent element when said
predetermined biasing force is removed.
2. The structure according to claim 1 wherein the detent element is
carried by the handle member, and the abutment element is carried
by the support.
3. The structure according to claim 2 wherein the abutment element
is mounted on said supporting member for adjustment to preselected
positions along the path of the handle member.
4. The structure according to claim 2 wherein abutment means are
provided on the supporting member near the OFF position of the
handle member, and are arranged for engagement with the detent
element, when the detent element is in extended position and
concurrently the handle member is in OFF position, for latching the
handle member in the OFF position.
Description
BACKGROUND OF INVENTION
1. Field of Invention
An external switch operating handle with a spring biased latching
detent frictionally held in latching position against the force of
its biasing spring.
2. Description of Prior Art
Heretofore, circuit breaker casings have been provided with a cover
carrying an external operating handle which is swung in a path
alongside the front face of the cover to ON and OFF positions for
moving the circuit breaker contact arms to corresponding
positions.
Such a structure is shown in U.S. Pat. No. 3,500,668, issued Mar.
17, 1970, and entitled "Switch Enclosure with External operating
Handle and Handle Locking Assembly." Therein the cover has an
abutment engageable by a latching detent carried by the handle for
holding the handle in OFF position when the detent is locked by
extraneous means in an extending position. The detent is spring
biased to retracted position.
The multi-pole electric circuit breaker having the handle lock of
the aforementioned patent includes movable contact arms which are
driven to ON and OFF positions with a snap action by operating
springs upon operation of the handle to tension the operating
springs and then move one end of each beyond dead center in each
selected direction of operation of the handle to ON and OFF
positions, respectively. Such a multi-pole electric circuit breaker
is disclosed in U.S. Pat. No. 3,560,899, issued Feb. 2, 1971, and
entitled "Electrical Circuit Breaker with Multi-Current Rating and
Improved Operating Means." As disclosed in a copending application
of Robert E. Dietz and Beryl W. Layton, Ser. No. 877,668, filed
Nov. 18, 1969, now U.S. Pat. No. 3,601,724, electrically operable,
remotely controlled latch means are provided for latching the
contact arm carriers of a circuit breaker in an open or OFF
position against the force of the operating spring while the handle
is held in an ON position so that the operating spring can drive
the contact arms to ON position upon release of the latch while the
handle remains in the ON position.
SUMMARY
The present invention is directed to an external operating handle
such as described in the above U.S. Pat. No. 3,500,668, but with an
abutment, or additional abutment as the case may be, positioned so
that it cooperates with a handle carried detent to hold the
operating handle in the ON position while the handle is biased
toward OFF position by the toggle springs of the operating
mechanisms of the circuit breaker due to latching of the contact
arm carriers thereof in an open position, as disclosed in the above
application, Ser. No. 877,668 of Nov. 18, 1969, now U.S. Pat. No.
3,601,724.
DESCRIPTION OF DRAWING
FIG. 1 is a front elevation of a molded-case circuit breaker
embodying the principles of the present invention, with the
operating handle in the OFF position;
FIG. 2 is a view similar to FIG. 1 showing the operating handle
latched in the ON position;
FIG. 3 is a cross sectional view taken on the line 3--3 in FIG. 2,
but showing a latching detent in retracted position;
FIG. 4 is an enlarged fragmentary sectional view taken on the line
4--4 in FIG. 2;
FIG. 5 is an enlarged fragmentary view taken on the line 5--5 in
FIG. 2; and
FIG. 6 is an enlarged fragmentary view taken on the line 6--6 in
FIG. 4.
Referring to FIGS. 1 and 2 of the drawing, a multi-pole molded-case
circuit breaker 1 similar to that disclosed in the aforementioned
U.S. Pat. No. 3,560,899 is shown.
The circuit breaker 1 includes a case having side walls 2 and a
cover 3 with a front wall 4. The interior structure is described in
detail in the aforementioned U.S. Pat. No. 3,560,899. Latching
means 6, as disclosed in the aforementioned copending application,
Ser. No. 877,668, now U.S. Pat. No. 3,601,724 are provided for
releasably latching the contact arm carriers in open or OFF
position.
A cross bar 7 is connected to the operating mechanisms of all three
poles of the circuit breaker and to a suitable linkage, indicated
generally at 8, which, in turn, is drivingly connected to a rocker
arm 9 mounted on a rock shaft 10 extending through the cover 3.
The circuit breaker 1 includes an exterior operating handle 11
which is fixedly mounted on the rock shaft 10. The handle 11 may be
swung to ON position for tensioning the springs of the operating
mechanisms of the circuit breaker while the contact arm carriers
are latched in an OFF position by latching means, such as disclosed
in the aforementioned copending application Ser. No. 877,668, now
U.S. Pat. No. 3,601,724 whereby the handle 11, while in the ON
position, is biased toward the OFF position by the toggle springs
so long as the contact arm carriers are latched in OFF
position.
The specific details of the interior structure of the circuit
breaker 1 and of the latching means 6 form no part of the present
invention, which is directed to the operating handle 11 and the
latching means therefor.
As mentioned, the handle 11 is operable to swing the arm 9 and
thereby the cross bar 7 to ON and OFF positions, selectively, and
to be swung by the arm 9 from an ON to an OFF position when the
contact arm carriers of the circuit breaker 1 are latched in OFF
position by the latching means 6. Further the circuit breaker 1 is
one in which, while the movable contact arm carriers are latched in
the open or OFF position by the latching means 6, the cross bar 7
is biased to the OFF position by the toggle springs of the
operating mechanisms of the circuit breaker. This biasing force of
the toggle springs is transferred through the linkage 8, rocker arm
9, and rock shaft 10 to the operating handle 11 so as to bias the
operating handle 11 to swing about the axis of the shaft 10 to the
OFF or open position of the circuit breaker, such as indicated in
solid lines in FIG. 1.
The handle has an outer end portion 15 in which a detent 12 is
arranged for engagement with and disengagement from a suitable
abutment on the front wall 4 of the cover 3. The detent 12 and all
mOving parts thereof, and their mounting in a cavity in the outer
end portion 15 of the handle 11 may be the same as in the
aforementioned U.S. Pat. No. 3,500,668.
The detent 12 comprises a flat piece of metal supported in the
handle 11 by a pivot 13 disposed in an elongated slot 14 in the
detent 12 so that the detent can be swung about the pivot 13 toward
and away from the cover 3 and also can be pulled slightly outwardly
endwise of the handle. For the purpose of locking the detent 12 in
extended position, should such be desired, it is provided with an
elongated slot 16 (FIGS. 3 and 5) arranged to receive hasps of one
or more padlocks. The detent 12 is provided with a finger 17 which,
while the handle 11 is in OFF position, can be moved into a slot 18
in the cover by moving the detent to extended position and when so
moved, is engageable with a side wall 19 of the slot 18 for holding
the handle in the OFF position. The detent 12 may be used to lock
the handle 11 in OFF position by suitable padlocks or to hold it in
ON position, selectively.
The handle and detent structure thus far described is fully
disclosed in the aforementioned U.S. Pat. No. 3,500,668.
In accordance with the present invention, means are provided which
cooperate with the detent 12 to hold the handle 11 in the ON
position against the biasing force of the toggle springs of the
circuit breaker operating mechanism. For this purpose, the cover 3
is provided with a recess 20 in which an abutment 21 is adjustably
mounted. The abutment 21 is secured in adjusted positions along the
path of the outer end portion 15 of the handle 11 by a screw 22
extending through an elongated slot 23 in the abutment. The
abutment 21 is positioned near the ON position of the handle 11 so
that, if the handle is swung to the ON position and the detent 12
moved to extended position, the detent finger 17 will lie closely
alongside the abutment 21. When the handle 11 then moves a very
slight distance toward OFF position under the biasing force of the
toggle springs, the side of the detent finger 17 facing toward the
OFF position of the handle 11 will engage the abutment 21 and
prevent swinging of the handle 11 to the OFF position so long as
the detent 12 is extended.
The detent 12 is biased toward a retracted position by a spring 24,
as described in the aforementioned U.S. Pat. No. 3,500,668. The
spring is chosen for the present purposes in relation to the
biasing force imposed on the handle 11 by the toggle springs of the
circuit breaker operating mechanisms when the handle is in ON
position and the movable contact arm carriers are latched in the
OFF position by the latching means 6. This relation is such that
the frictional force between the side of the finger 17 and the
juxtaposed face of the abutment 21 is enough to restrain movement
of the detent 12 to retracted position by its biasing spring 24.
Accordingly, if the handle 11 is moved to ON position while the
circuit breaker contact arms are latched in OFF position, the
biasing force of the toggle springs of the circuit breaker
operating mechanisms will urge the handle 11 toward the OFF
position. This biasing force is such that the frictional resistance
to movement of the detent 12 toward retracted position overcomes
the force of the spring 24, whereby the detent remains in the
extended position and latches the handle 11 in ON position. If the
latching means 6 is operated to release the circuit breaker contact
arms, the biasing force of the circuit breaker operating mechanisms
toggle springs biasing the handle 11 to OFF position is eliminated.
As a result, the pressure between the finger 17 and abutment 21 is
reduced below a predetermined minimum value whereupon the spring 24
is adequate to, and does, retract the detent 12 and thereby
releases it from the abutment 21. The handle 11 is then free to be
swung to OFF position and operated in the usual manner.
It is apparent, therefore, that by the use of the detent structure
disclosed in the aforementioned U.S. Pat. No. 3,500,668 with an
abutment in the proper position, the handle 11 can be releasably
held in the ON position, thereby providing a very simple and
effective means for retaining the handle 11 in ON position so long
as the contact arms are latched in open or OFF position.
* * * * *