U.S. patent number 3,867,602 [Application Number 05/409,598] was granted by the patent office on 1975-02-18 for contact cluster for arcing and current carrying means in a circuit breaker.
This patent grant is currently assigned to McGraw-Edison Company. Invention is credited to Melbourne G. Jawelak.
United States Patent |
3,867,602 |
Jawelak |
February 18, 1975 |
CONTACT CLUSTER FOR ARCING AND CURRENT CARRYING MEANS IN A CIRCUIT
BREAKER
Abstract
A contact cluster for arcing and current carrying in a circuit
breaker including a plurality of contact fingers pivotally
supported on a cylindrical base member and uniformly spaced about
the base member by a spacer. Garter springs are provided about the
contact fingers to bias them into engagement with both the base
member and a movable contact inserted between the free ends of the
contact fingers. Arc resistant materials are provided on the
contact fingers and on the movable contact on the portions between
which arcing takes place.
Inventors: |
Jawelak; Melbourne G.
(McMurray, PA) |
Assignee: |
McGraw-Edison Company (Elgin,
IL)
|
Family
ID: |
23621190 |
Appl.
No.: |
05/409,598 |
Filed: |
October 25, 1973 |
Current U.S.
Class: |
218/146; 439/246;
200/253.1; 439/181 |
Current CPC
Class: |
H01H
1/385 (20130101) |
Current International
Class: |
H01H
1/38 (20060101); H01H 1/12 (20060101); H01h
001/38 () |
Field of
Search: |
;200/163,282,287,288,258,260,261 ;339/64,255P,111 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Broome; Harold
Attorney, Agent or Firm: Gealow; Jon Carl
Claims
What is claimed as new and is desired to be secured by Letters
Patent of
1. A contact cluster arrangement for a circuit interrupter having
arc suppressive and continuous current carrying abilities
comprising:
a. a base member having a mounting portion and a projecting contact
support portion having a cylindrical external surface, with a
groove formed therein,
b. a plurality of contact fingers each having a first pivotally
supported end and a second movable contact engaging end, said
pivotally supported ends engaging said groove formed in said
projecting contact support portion of said base member at two
separate points so as to provide improved current transfer
therebetween,
c. a spacer means supported on said projecting contact support
portion and positioned to engage said contact fingers between said
pivotally supported ends and said movable contact engaging ends to
uniformally space said contact fingers about said projecting
contact support portion,
d. at least one garter spring encircling said contact fingers
between the point of engagement with said spacer means and said
first pivotally supported end to bias said pivotally supported ends
of said contact fingers into engagement with said contact support
portion,
e. at least one garter spring encircling said contact fingers
between the point of engagement with said spacer means and said
movable contact engaging ends to bias said movable contact engaging
ends into contact with a movable contact when moved therebetween,
and
f. arc resistant material provide on the movable contact engaging
ends of said contact fingers and said portion of said movable
contact engaging
2. The contact cluster arrangement as set forth in claim 1 wherein
the outer periphery of said spacer means is provided with a series
of uniformly spaced notches, each of which receives the central
portion of one of said contact fingers to maintain said contact
fingers uniformly spaced about said central support member, the
depth of said notches in said spacer means is such as to provide
for slight inward movement of said movable contact engaging ends of
said contact fingers upon withdrawal of
3. The contact cluster arrangement as set forth in claim 1 wherein
said projecting contact support portion of said base member is
provided with a central base to provide a passage for exhausting
arced products from the contact cluster.
Description
BACKGROUND OF THE INVENTION
Various contact structures have been and are being utilized for
under load circuit breaking within arc extinguishing chambers in
liquid dielectric filled type circuit breakers. Generally the
movable contact can be characterized as a male contact and the
fixed contact as a female contact. Various arrangement have been
provided for providing spring pressure on the female contact or
contacts to insure contact force between the movable and fixed
contacts. One such arrangement using leaf type springs is disclosed
in U.S. Pat. No. 3,107,418 assigned to the assignee of the instant
application. A similar arrangement using leaf type springs is also
shown in U.S. Pat. No. 3,519,774-Rietz.
It is an object of this invention to provide a contact cluster for
a circuit breaker which will provide improve arcing and sustained
current carrying ability, while at the same time utilizing a
structural arrangement, the components of which are readily
manufactured and assembled without undo difficulty.
SUMMARY OF THE INVENTION
The foregoing object is accomplished in accordance with this
invention in one form thereof, by providing a contact cluster base
member having a mounting portion and a cylindrical contact finger
supporting portion. One end of each of a plurality of contact
fingers is pivotally supported in an external groove on the
cylindrical portion. A spacer is also supported by the cylindrical
portion and engages notches in the central portion of the contact
fingers to uniformally space the contact fingers within the contact
cluster assembly. Garter springs are placed around the contact
fingers between the central portion engaging the spacer and the
ends of the contact fingers engaging the groove in the base member
to hold the contact fingers in engagement with the base member.
Additional garter springs are placed around the contact fingers
between the central portion engaging the spacer and the ends of the
fingers which engage a movable contact to bias the fingers into
contact with the movable contact. The tip of the movable contact
and the ends of the contact fingers engaging the movable contact
are provided with an arc resistant material such that as the
movable contact is withdrawn from the contact fingers, arcing takes
place only between arc resistant materials.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a side elevational view of the preferred embodiment of
the circuit breaker contact cluster of this invention;
FIG. 2 is a bottom elevational view of a portion of the circuit
breaker contact cluster shown in FIG. 1;
FIG. 3 is an elevation view of the circuit breaker contact cluster
taken along the line 2--2 in FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to the drawing, the contact cluster 2 of this invention
is shown to be assembled on a mounting portion 4 having a
cylindrical member 6 extending from a mounting portion 8. The
mounting portion 8 is a circular configuration, with a wedge shaped
portion removed as best seen in FIG. 2. The mounting portion is
provided with mounting holes 10,12,14 and 16 for securing it to the
circuit breaker assembly by suitable fastening means such as
bolts.
The cylindrical member 6 is provided with a central bore 18 which
has an enlarge diameter upper portion 20 which receives the end of
the male contact tip 22 shown in a disengaged position in FIG. 3. A
smaller diameter portion 24 of the bore 18 extends from the
enlarged portion 20 to a frustoconical portion 26 extending through
the mounting portion 8. The central bore 18 including portions
20,24 and 26 together with the wedge shaped open portion of the
base provide a passage for exhausting arced products from the
contact cluster.
A cluster of six contact fingers 28,30,32,34,36 and 38 are
supported on the cylindrical member 6. The contact fingers are
provided with rounded lower ends such as 40 and 42 of fingers 28
and 34 as shown in FIG. 3. These rounded ends are pivotally
received in groove 44 formed in the outer surface of cylindrical
member 6. The geometry of the groove 44 is such as to provide two
definite points of contact with each finger, 46 and 48 for finger
28 and 50 and 52 for finger 34.
A spacer 54 is mounted at the upper end of cylindrical 6 to
uniformly space the contact fingers. The spacer 54 has a
cylindrical central bore 56 which is sized to fit in a notch 58
provided at the end of cylindrical member 6. The outer periphery of
the spacer 54 is provided with series of uniformly spaced notches
into which the central portion of the contact fingers are received.
As shown in FIG. 3, the contact fingers are provided with notches,
notches 60 and 62 for fingers 28 and 34 to hold the finger in
position with respect to the spacer 54. As shown by spacer portions
64 and 66 and 68 in FIG. 1, the spacer extends outwardly between
the contact finger to space the contact fingers.
The contact fingers are held in engagement with the spacer 54 and
the groove 44 by a pair of garter springs 70 and 72. Received in
locating grooves 74 and 76 in the outer surface of the contact
fingers. Similarly the upper ends of the contact fingers, the tips
of which engage the male contact tip 22 are biased into engagement
by a pair of garter springs 78 and 80 received in locating grooves
82 and 84.
The tips of the contact fingers are provided with an arc resistant
material as shown by 86 and 88 for fingers 28 and 34 in FIG. 3.
Similarly the end 90 of male contact tip 22 is provided with an arc
resistant material. Thus, the arc resistant material on the ends of
the contact fingers engages the arc resistant material on the end
of the male contact tip as they are disengaged, such that any
resultant arc is drawn only between arc resistant materials. The
geometry of the spacer 54 with repsect to the contact tips of the
contact fingers is such as to permit a slight collapse of the
contact fingers as the moving contact is withdrawn. Or, in the case
of moving contact insertion, the contact fingers are slightly
expanded, i.e. lifted off of the bases of the notches in the
spacer.
While as previously set forth, arc resistant material is provided
arc interruption, the contact fingers 28,30,32,34,36 and 38,
mounting portion 8 and movable contact 22 are made of suitable
conductive material for continuous current carrying ability.
It should be apparent to those skilled in the art, that while what
has been described is considered at the present to be the preferred
embodiment of this invention, in accordance with the Patent
Statutes, changes made be made in the disclosure contact cluster
without actually departing from the true spiral and scope of this
invention.
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