close

Вход

Забыли?

вход по аккаунту

?

Патент USA US2105591

код для вставки
Jan. 1a, 1938.
G. GooDwm
ELECTRIC FUSE
Filed ‘June 19, 1935
2,105,591
Patented Jan. 18, 1938
2,105,591‘
UNITED STATES PATENT OFFIQE
2,105,591
ELECTRIC FUSE
George Goodwin, Avon, Mass, assignor to Royal
Electric Company, Incorporated, Avon, Mass,
a corporation of Massachusetts
Application June 19, 1935, Serial No. 27,313
14 Claims.
This invention relates to electric fuses and, in
certain aspects, more particularly to such fuses of
the plug type.
One object of this invention is to‘ provide a
fuse of cheap construction and yet which is
reliable and eii’ective.
Heretofore it has been usual to make certain
portions of plug fuses of porcelain, and when
glass tops have not been used, to attach windows
10 of mica or the like over the top ends of the
porcelain members as by metal ferrules. One
of the disadvantages of this construction is that
the porcelain parts cannot be made commercially
to accurate dimensions and this adds to the
15 difiiculty and expense of assembly.
Another
disadvantage is that metal parts are exposed for
engagement with the ?ngers where mica windows
have been employed, and while this metal is out
of contact with any electrical parts and actually
20 presents little possibility of danger, yet many
people do not like to touch metal parts of elec
trical apparatus.
One object of the present invention, therefore,
is to produce a construction wherein material
moldable to exact measurements may be em
ployed and wherein metal parts are not posi
tioned where it is necessary to touch them when
removing or replacing the fuse by hand.
A further object is to provide a construction
by which assembly and securement of the parts
is facilitated.
Another object is to provide visual indication
of the condition of the fuse, whether bad or
good, which will give a direct indication, instead
Cl of indicating by changes in appearance only,
which are not always understood by one not
familiar with fuses.
For a more complete understanding of this in
(Cl. 200-121)
Figure 9 is a view partly in section similar to
Figure 2, but showing a further modi?cation.
Figure 10 is a. fragmentary perspective showing
the fuse link and indicator of Figure 9.
Referring ?rst to Figures 2 and 3, at I is indi
cated a casing of insulating material, such, for
example, as a moldable composition of a syn
thetic resin or the like, such material being
capable of being molded to precise dimensions.
This casing is provided with an upper portion 2
of relatively large diameter, terminating in a rim
3 which may be roughened on its outer side as
at 4 (see Figure 1) to facilitate engagement of
the fuse by the ?ngers for screwing into and out
of its threaded receptacle. The lower portion
through.
.
The top of the casing l on its inner side is of
enlarged diameter or counterbored as at 8 to
form a shoulder 9 on which may rest a window
member ID of mica or other suitable transparent
material. Above the shoulder 9 is positioned
an inwardly extending lip l l, which, as shown
best in Figure 4, is not continuous but may be
formed of segmental portions with intervening
spaces as at 13. By so forming the lip it may
be molded in place, the portions i3 permitting the
removal of the molded casing from the mold in
which it is formed. This lip H i'orms means for
retaining in position a disk 14 which may be
made of thin metal dished inwardly to forms.
?aring rim i5 which is preferably formed with
serrations I6 about its margin. By forcing this 5
disk ! 1% inwardly after the window member 10 has
been placed in position, the marginal edges of
this disk at the rim 15 may be sprung in under
vention, reference may be had to the accompany~
the lip l I. This acts to ?rmly retain the window
ing ‘drawing in which
in position and it cannot be readily removed _
Figure 1 is a perspective of a plug fuse con
structed in accordance with this invention.
Figure 2 is a central vertical section to a larger
scale on line 2—2 of Figure 1.
Figure 3 is a section on line 3--3 of Figure 2.
Figure 4
Figure 5
Figure 2.
Figure 6
fuse link.
Figure 7
is a top plan of the fuse.
is a detail section on line 5~5 of
is a fragmentary perspective of a
is a view similar to a portion of
Figure 3, but showing a modi?cation.
Figure 8 is a perspective of a portion of the
same construction.
i ‘
of the casing is of reduced diameter as at 5 and
is partly closed off at its lower end by a base 6
having a central hole or perforation "I there
thereafter, and it is quite capable of withstand
ing all the pressure which is exerted within the
fuse casing when the fuse blows, such pressure
acting to expand the rim 15 into closer engage
ment with the internal wall of the casing i im
mediately below the lip H.
n
For engagement with the interior threads of
the socket in which such a fuse is placed, a
threaded metal shell 2t‘; is employed, the upper
unthreaded edge 2| of which may engage in a '
slightly reduced diameter portion 22 in the outer
face of the portion 2 of the casing i. The lower
end of the shell 20 is iii-turned as at 32 and ex
tends beneath and in contact with the base 6 of
the casing. This base 6 is preferably provided
2
2,105,591
with notched out of portions as at 23 into which
the material of the shell may be pressed as at
24 to lock the shell 22 against rotation with the
casing I so that by rotation of the casing I be
tween the ?ngers, the shell 20 may be screwed
into or out of its socket.
_ At 25 is indicated a fuse link which is shown
blown, a portion of it is positioned back of the
perforation 55, this showing therethrough a
legend such as “good” indicating that the fuse
link has not blown. On the blowing of the fuse
link the spring 50 is released, thus moving the
legend “good” out from registry with the open
ing 56 and presenting another portion of the
as, provided with an intermediate upwardly
looped portion 26 provided in its top portion with
'10
a reduced cross section part 2".‘ to localize the
point of rupture of the link when the fuse blows.
One of the downwardly extending end portions
of the fuse link such as 28 passes downwardly
through a perforation 29 in the annular portion
30 of the casing ! and into the space between
the inner face of the shell 20 and the outer face
of the reduced diameter portion 5 of the casing
I. At its lower end the portion 28 passes be~
tween the base 6 of the casing ! and the shell 20
and its extreme end is folded about the inner
edge of this shell, passing downwardly through
a central opening 35 thereof. The opposite end
portion 3'! of the fuse link is turned inwardly and
is formed as an annulus 38, resting upon the
top of the base ii of the casing l. These parts
are all secured together by a rivet M which is
shown as tubular and which passes through an
insulating washer 4|, through the opening '1 of
the base 8 and through the annulus 38 and is
30 headed over onto the top of this annulus. This
card in register therewith on which portion may
be shown the legend “bad”, indicating that the
fuse link has blown.
In Figures '7 an: 8 another type of indicator
is shown in which a spring 50, similar to the
spring 58 shown in Figures 2 and 3, is employed
and which normally rests against one side edge of
the fuse link 25. The upper end of the spring
60, however, is curved over to loosely engage one
end of a tilting indicating member 65, which, as
shown in Figure 8, is pivoted within a slot 66 in a
partition member ‘61 which may be seated on a
plurality of annular shoulders 68 which may be
integral with the casing wall. The indicator 65
may have its ends notched as at Til so as normal~
ly to be retained in rocking position in the par
not only secures the inner end of the fuse link
to the upper face of the casing base 8, but also
clamps the opposite folded end of the fuse link
about the lower edge of the shell 20 out of elec
trical connection with the rivet 40. The rivet
40 likewise serves as the central terminal of the
fuse, the shell 20 forming the other terminal.
In order to facilitate the insertion of the fuse
portion 28 into the proper position, the interior
40 wall of the upper portion 2 of the casing is pro
vided with a pair of guide lugs 45 (see Figures 3
tition 61 and normally present one face upwardly
toward the opening 56 in the window retainer,
this face having an indication such as “good”,
showing the fuse in workable condition. As
soon as the fuse blows and releases the upper end
of the spring 69, the indicator 65 is turned about ,
its axis to present its opposite side uppermost, i
this side showing the “bad” indication as shown
in Figure 8, so that this “bad” indication is visible
through the window and the opening 55 of the
window retainer.
With either of these forms of indicator, the ‘
recesses 23 and the depressions 24 of the casing
and shell, respectively, hold the parts in their
desired relationship with the spring 50 or 66 at
substantially right angles to the plane of the
fuse link.
In Figures 9 and 10 a different form of indi
and 5), having their top edges rounded off, to cator is employed in which the spring '15 is ar
serve as a guiding channel into which the fuse ranged in the plane of the fuse link and acts to
end 28 may be placed and by which this end is separate the two portions of the fuse link when
guided down through the opening 29 as far as it blows at its reduced diameter portion 21. 1
may be permitted by stop extensions 280 on the This spring '15 is shown as supporting the in
portion 28. The shell 20, casing l, fuse element dicator card 16, which when the fuse link is
25, and the washer 4] having been assembled, whole presents a “good” indication opposite to
the rivet 40 is inserted in position. By heading the opening 56 of the window retainer and after 50
over the rivet 40, these several parts are secured the fuse has been blown presents the “bad” indi
cation.
together in correct position, after which the win
From the foregoing description of certain em
dow l0 and its retainer 12 may be placed in posi
bodiments of this invention, it should be evident
tion.
In order to give a positive indication of the to those skilled in the art that various changes LI
condition of the fuse element as to whether or
not it is blown, means such as shown in Fig
ures 2 and 3 may be employed. Referring to
these ?gures, at 50 is shown a leaf spring ele
ment which may be secured at one end as at 5| in
any suitable manner to the casing i. As shown
its end portion is bent to the shape of the casing
wall and its extreme end 52 is inserted in a per
foration 53 in the portion 30 of the casing. This
spring is looped upwardly and at its upper end
65 is bent to form a hook portion 54 into which is
inserted an indicating card 55. Below this card
the spring 50 bears against one side edge of the
fuse link 25 so that when the fuse link blows,
the spring 50 is free to unbend somewhat so as
70 to move the indicator card 55 laterally from its
normal position before the fuse link was blown.
The window retaining disk [4 is shown as pro
vided with an opening 56 through which a por
tion of the window is exposed and when the card
75 55 is in its normal condition before the fuse is
and modi?cations might be made without depart- '
ing from the spirit or scope of this invention as
de?ned by the appended claims.
I claim:
1. A fuse comprising a casing, a threaded metal
shell, a fuse link, and a fastening element secur- i“:
ing said casing and shell together and one end
of said fuse link about an edge of said shell.
2. A fuse comprising a casing, a threaded metal
shell, a fuse link, and .a fastening element secur
ing said casing and shell together and one end of
said fuse link about an edge of said shell, said
element also securing the other end of said link
to said casing.
3. A fuse comprising a casing, a threaded metal
shell, a fuse link, and a fastening element secur<
ing said casing and shell together and one end of
said fuse link to said shell, said element also
securing the other end of said link about an edge
of said casing and itself forming a fuse terminal.
4. A fuse comprising a tubular casing having‘75
2,105,591
its lower portion of reduced external diameter,
a threaded metal shell spaced from said reduced
Cl
portion and having its lower end in-turned be
neath said lower portion, and a fuse link, said
casing having a hole therethrough leading into
said space, and said fuse link extending through
said hole and secured about an edge of said shell.
5. A fuse comprising a tubular casing having
its lower portion of reduced external diameter,
10 a threaded metal shell spaced from said reduced
portion and having its lower end in-turned be
neath said lower portion, and a fuse link having
its end portion folded over the inner edge of said
shell, said casing having a hole therethrough
leading into said space and said fuse link extend
ing through said hole into said space, and means
clamping said end portion, shell, and casing to
gether.
6. A fuse comprising a tubular casing having
its lower portion of reduced external diameter, a
threaded metal shell spaced from said reduced
portion and having its lower end in-turned be
neath said lower portion, and a fuse link having
its end portion folded over the inner edge of said
shell, said casing having a hole therethrough
leading into said space and said fuse link extend
ing through said hole into said space, and means
clamping said end portion,‘ shell, and casing to
gether, said clamping means comprising a termi
nal for the other end of said link.
7. A fuse comprising a tubular casing, a thread
ed metal shell having its lower end in-turned
beneath the lower portion of said casing, a fuse
link having its end portion folded over the inner
edge of said shell at its lower end, and means for
clamping said fuse link shell and casing together.
8. A fuse comprising a casing, a threaded metal
shell having an end inturned over an end of said
casing, an insulating washer engaging the outer
40 face of said inturned end, a fuse link in said
casing having one end engaged between said
washer and casing and in contact with said shell,
said shell having an opening through said end,
and a rivet extending through said opening and
said washer and engaging the opposite end of said
link for securing said casing, shell, fuse link and
washer together, said rivet also serving as a termi
nal for said fuse link.
9. A fuse comprising a casing, a threaded metal
50 shell having an end inturned over an end of said
casing, an insulating washer engaging the outer
face of said inturned end, a fuse link in said
casing having one end engaged between said
washer and casing and bent about the edge of
a: Li said shell, said shell having an opening through
said end, and a rivet extending through said
opening and said washer and engaging the op
posite end of said link for securing said casing,
shell, fuse link and washer together, said rivet
60 also serving as a terminal for said fuse link.
10. A plug fuse comprising a casing of insu
3
lating material having an open upper end and a
lower end provided with a central opening, a
threaded metal shell having its upper edge engag
ing the side of said casing and its lower end in
turned beneath the lower end of said casing and
having an opening therethrough, said shell and
casing having a space therebetween, a fuse link
having a loop portion upstanding within said
casing, said casing having an opening there
through extending into said space and through
which one end portion of said link extends, the
end of said portion engaging about the edge of
said shell at said shell opening, an insulating ring
beneath said shell, a rivet extending through said
ring and central casing opening and clamping 1 5
said in-turned shell end to the outside of said
casing out of electrical connection with said rivet
and the opposite end of said link to the inner
side of said casing and in electrical connection
with said rivet, and a window secured in the open
upper end of said casing.
11. A fuse comprising a casing having an open
top provided with a counterbored portion having
an inwardly extending lip spaced from the base
of said portion, a window member seated in said ‘
counterbored portion, and a downwardly dished
member having an opening therethrough for ex
posing a part of said window and sprung into
position beneath said link and retaining said win
dow in position.
12. A fuse comprising a casing having an open
top provided with a counterbored portion having
an inwardly extending annular lip spaced from
the base of said portion, a window member seated
on the‘ base of said counterbored portion beneath
said lip, and a window retainer dished inwardly
to form a ?aring annular rim sprung in and en
gaging beneath said lip and bearing on said mem
ber.
13. A fuse comprising a casing having an open
top provided with a counterbored portion having
an inwardly extending annular lip spaced from
the base of said portion, a window member seated
on the base of said counterbored portion beneath
said lip, and an inwardly dished thin metal mem
ber having a ?aring annular rim sprung in and
engaging beneath said lip and bearing on said
window member.
14. A fuse comprising a casing having a win
dow, a fuse link in said casing and. having a weak
ened portion, a leaf spring bearing against said
link and having one end secured whereby when
said fuse parts at said weakened portion a por
tion of said spring is freed for motion away from
its normal position, and a fuse-condition indicator 65
pivotally secured in said casing to present either
of two faces to view through said window in posi
tion to be turned about its pivot by said spring
motion and present the face indicating that the
fuse has blown.
60
GEORGE GOODWIN.
Документ
Категория
Без категории
Просмотров
0
Размер файла
560 Кб
Теги
1/--страниц
Пожаловаться на содержимое документа