Note: Descriptions are shown in the official language in which they were submitted.
1325822
FUSE EJECTOR
CO/89
BACKGROUND OF THE INVENTION
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FIELD OF THE INVENTION
This invention relates to fuse ejectors for incor-
poration into fusible switches and fuse holders.
DESCRIPTION OF THE PRIOR ART
In the design of fusible switches and fuse holders,
insulating barriers are usually located between adjacent fuses.
The fuses are mounted in fuse clips which are connected to
their respective line connectors or switchblades. The fuse
clips comprise spring jaws and substantial force is usually
required to extract the fuse from the fuse clip. Forces in
the neighbourhood of 20 - 30 lbs. may be required. Because
of the presence of the insulating barriers, there is frequently
no room to permit grasping the fuse and the plier-type fuse
removal tool cannot be inserted between the fuses. This pro-
blem is particularly evident with short fat fuses, particularly
the Canadian type J fuse. Unfortunately, one common technique
is to use a screwdriver or the like to lever the fuse loose.
There is the possibility excessive force may be applied and
cause damage to the fuse or to the adjacent fuse or portions
of the assembly.
Prior solutions have usually involved loops surround-
` ing the end of the fuse which loops have an extension which may
be pulled, thus pulling one end of the fuse loose from the fuse
clip This form of plastic loop is shown in V.S. Patent No.
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4,696,528, issued September 29, 1987. It will be seen thatthe whole force required to extract the end of the fuse from
the fuse clip must be supplied by the operator by pulling on
the puller. After the fuse has come free from the fuse clip,
the puller is restricted from further motion by means of an
extensible plastic member. It will be seen, however, that the
remaining force, which cannot immediately be terminated, is
then applied to the apparatus which not only may be destructive
; to the apparatus, but also may hurt the operator where the
finger is inserted through the puller.
A similar extractor is shown in U.S. Patent No.
4,671,588, issued June 9, 1987, which operates with a rolling
motion which makes the fuse somewhat easier to remove but is
still subject to the same objection in that the remnant force
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is still applied to the puller after the fuse has been removed
and can result either in impact force on the mechanism as a
whole or removal of the puller from its mounting post. It
will also be seen that both the preceding pullers require modi-
fication of the structure to accommodate the puller.
SUMMARY OF THE INVENTION
The present invention, rather than being an extractor
is an ejector, which may be fitted to a standard fusible switch
;~ or fuse holder without modification of the design. The mechan-
ism is mounted on the fuse clip attaching screw and, by means
of a lever action, ejects one end of the fuse from the fuse
;~ clip. The direction of force applied to the ejector is essent-
ially parallel to the fuse. The ejector consists of a lever
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mechanism pivotally mounted in the fuse holder with an insul-
ating portion projecting outward beyond the end of the fuse
in a location easily accessible to the operator. The force
is applied to the lever in the direction parallel to the fuse
and the lever rotates ejecting the end of the fuse from the
fuse clip. At the same time it rotates releasing the finger
of the operator so that excessive force is not applied to the
fuse holder or switch mechanism itself. In its inoperative
position, the ejector applies no substantial force on the end
of the fuse.
It is, therefore, an object of the invention to pro-
vide a simple ejector mechanism which may be fitted to fusible
switches or fuse holders to permit the convenient ejection of
one end of the fuse.
It is a further object of the invention to provide a
fuse ejector which does not apply objectionable loads to the
switch mechanism or box or holder during its operation.
It is a further object of this invention to provide
fuse ejectors which may be retrofitted to many fused switch
mechanisms and fuse clips without modification of the mechanism
itself.
~ These and other objects may be obtained in a manner
'~ which will become apparent in the detailed description of the
~' invention and the drawings wherein:
Figure 1 is a view, partially in section, of a switch
including a fuse mounted therein and incorporating the fuse
ejector of our invention.
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4 1325822 CO/89
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Figure 2 is a view similar to Figure 1 showing the
fuse in its ejected position.
Figure 3a is a view of the ejector mechanism as
viewed from III-III in Figure 1.
Figure 3b is a view of the ejector mechanism at
section IV-IV in Figure 3a.
Considering first Figure 1, there is shown a fuse 5
mounted between a pair of fuse clips 6 and 7. As will be seen,
the fuse clip 7 is connected to the pivot of a blade switch,
the pivot mounting being designated 8. The fuse clips 6 and 7
are mounted on the insulating portion of the switch body, this
whole insulated body being designated 9. Each fuse clip is
mounted on the body by means of a screw. The screw 10 mounts
~; the fuse clip 6 and screw 11 mounts the fuse clip 7.
To this point the apparatus is a standard fusible
`!~ switch, howevex, it will be seen that the switch has been modi-
j fied by introducing an ejector comprising a lever member 12
mounted on a mounting bracket 13. The lever member 12 and its
mounting bracket 13 may be more clearly seen in Figures 3a and
3b. The lever member 12 may be seen to consist of two essent-
ial parts, projecting arm 14 which is accessible from the front
of the fusible switch and protrudes beyond the plane of the
surfaces of the fuses in the switch, and a portion which pro-
'! jects sideways and protrudes underneath the fuse designated 15.
, 25 The lower surface of member 15 is of arcuate shape, curved to
blend smoothly into the operating member at 16, as may be seen
more clearly in Figure 3b. The lower portion of the ejector
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1325822 CO/89
mechanism, that is portion 15, includes in its lower surface
a trough having sidewalls 17 and 18. Each of these walls has
a longitudinal protrusion substantially parallel to surface
15. These protrusions 19 and 20 extend from a web 21 (Figure
3b) formed in the lower surface of portion 15 to the outermost
arcuate surface of member 15. The bracket 13 is arranged to
fit closely within the trough walls 17 and 18 with sufficient
clearance to permit movement. A pair of notches in the mount-
ing bracket, designated 22 and 23, co-operate with the protrus-
ions 19 and 20 to captivate the mounting bracket 13 in the
trough and prevent it from being drawn vertically downward out
of the trough once it has been slid into position. This up-
wardly projecting portion of the mounting bracket 13 is joined
to the lower mounting portion of the bracket substantially at
right angles. The lower mounting portion, includes a perfor-
ation of sufficient diameter to accept the mounting screw 11.
In order to retrofit a switch with the ejector, the
fuse or fuses are removed, the fuse clip mounting screw 11 is
removed, the mounting bracket 13 is aligned over the hole in
the fuse clip and screw 11 once more installed and tightened.
The ejector lever now may be rotated on its bracket into its
upright position as illustrated in Figure 1 and the fuse may be
reinserted.
In operation, the user simply pushes on arm 14 in the
direction shown in Figure 1 by arrow 26, causing the ejector
mechanism to rotate on its mounting bracket 13. The ejector
rocks on its arcuate lower surface and the outer tip 27 of
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6 132~822 CO/89
member 15 pushes the ferrule of the fuse upwards until the
position shown in Figure 2 is reached when the ferrule of the
fuse is essentially comp;etely disconnected from the fuse
clip. A protrusion 29 on one of the sidewalls of the body 9
extends under and serves to support bracket 13 during this
operation.
It will be seen that the force applied by the user
is parallel to the fuse body and as the fuse is released the
lever rotates in such a manner that the force applied by the
user's hand will be reduced because the lever is approaching
the direction of the arrow 26. It will, therefore, be evident
that any remnant force, which the user is unable to stop apply-
ing, does not cause substantial impact on the fuse mechanism or
any part of the fused switch.
While the apparatus has been described in association
, with a single fuse, it will be evident that one apparatus will
,~ be mounted within the fuse clip at one end of each of the fuses
within the fused switch. It will also be evident that the
particular material chosen for the purpose is a matter of
choice, but it will be advantageous if the lever mechanism is
molded from a relatively strong insulating material and the
mounting bracket formed from a stiff, even springy, metallic
member which need only be chosen for its strength since it
does not itself carry any of the electrical current in the
switch. It will also be evident that the particular proport-
ions of the mechanism are not critical but it is advantageous
that the lower portion be pivoted directly below the fuse
ferrule and, therefore, the structure shown, with the mounting
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7 132~822 CO/89
bracket placed within the fuse clip, ensures its proper loc-
ation.
The lever portion, obviously, must be offset to one
side to permit it to project between adjacent fuses. It may,
however, be quite thin and thus the fuses may be placed as
closely together as is electrically permissible. If the mat-
erial chosen for the lever is suitable, it will not in any way
affect the rating of the apparatus. It will also be evident
that the dimensions of the device will depend upon the size of
the fuses being dealt with and, in most cases, the projection
15 will closely approach the diameter of the fuse ferrule.
While the invention has been described in association
with a fusible switch, it is evident that it is applicable to
any clip mounted fuse equipment whether or not the equipment
includes other electrical equipment.
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