CLOSING DEVICE

DISPOSITIF DE FERMETURE

English Abstract

An over-centre closing device for closing together first and second
parts of an article, comprising a lever pivotally attached to an arm which
is pivotally mounted to the first part of the article, the lever having an
engagement surface which engages the second part of the article and
fastens the two parts of the article together when the lever is in its
over-centre position in use, wherein the lever has an extension which extends
beyond the engagement surface and which may cooperate with the second
part of the article to provide initial closing leverage during an initial
stage
of closing the article and which allows the engagement surface to contact
the second part of the article to provide final closing leverage during a
final stage of closing the article.

French Abstract

Dispositif de fermeture à détente brusque destiné à fermer ensemble des première et seconde parties d'un article, qui comprend un levier attaché pivotant à un bras monté pivotant sur la première partie de l'article. Ledit levier possède une surface de contact qui vient en contact avec la seconde partie de l'article et attache les deux parties de l'article ensemble lorsque le levier est dans sa position décentrée. Le levier possède une partie saillante qui s'étend au-delà de la surface de contact et qui peut coopérer avec la seconde partie de l'article pour fournir un effet de levier initial en vue de la fermeture pendant une étape initiale de fermeture de l'article et qui permet à la surface de contact de venir en contact avec la seconde partie de l'article pour fournir un effet de levier final de fermeture pendant l'étape finale de la fermeture dudit article.

Claims

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CLAIMS:
1. An article comprising first and second
parts (2,3), which can be closed together, and an over-
centre device (6) for effecting said closure, the over-
centre device (6) comprising a lever (11) pivotally attached
to an arm (9) which is pivotally mounted to the first
part (2) of the article, the lever (11) having an engagement
surface (21) at a free end of the lever (11) which engages
the second part (3) of the article and fastens the two
parts (2,3) of the article together when the lever (11) is
in its over-centre position in use, characterised in that
the lever (11) has an extension piece (15) which extends,
seen along the length of the lever (11), beyond the
engagement surface (21) at the said free end of the
lever (11), and which is arranged to cooperate with the
second part (3) of the article to provide an initial closing
leverage during an initial stage of closing the
article (2,3), and which allows the engagement surface (21)
to contact the second part (3) of the article to provide
final closing leverage during a final stage of closing the
article.
2. An article and over-centre device according to
claim 1, wherein the extension piece (15) on the lever (11)
is arranged so that when the first and second parts (2,3) of
the article are closed, it cooperates with the second
part (3) of the article to provide an initial opening
leverage during an initial stage of opening the article.
3. An article and over-centre device according to
claim 1 or 2, in which the second part (3) of the article
has a protrusion (17), and the cooperation of the extension

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piece (15) of the lever (11) with the second part (3) of the
article comprises contact between the extension piece (15)
and the protrusion (17).
4. An article and over-centre device according to
claim 3, in which the extension piece (15) has a hook-like
part (16) which engages the protrusion (17) during the
cooperation of the extension piece (15) with the
protrusion (17).
5. An article and over-centre device according to any
one of claims 1 to 4, wherein the article comprises a
housing.
6. An article and over-centre device according to
claim 5, wherein the first and second parts of the
article (2,3) comprise two portions of a split ring, and the
over-centre device (6) closes the split ring in a clamping
position in use.
7. An article and over-centre device according to
claim 5 or 6, wherein the housing comprising a cable splice
closure.

Description

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CLOSING DEVICE
The present invention relates to closing devices of the over-centre type,
particularly for closing housings, especially cable splice closure housings,
either as
= part of the housing itself or as part of a clamp for fastening together
first and second
parts of the housing.
EP 0 094 848B (Raychem) discloses an enclosure for protecting cable
joints from the environment. The enclosure comprises two parts e.g. a closure
and a
base. The two parts are held together by a clamping ring which forces flanges
on the
two parts together. No details are given of the clamping ring.
US 5 059 748 (Raychem) discloses a butt splice cable splice closure
comprising a dome and base held together by a clamping ring. The ring is in
two
parts, which are hinged together at their ends opposite the hinge by a
threaded bolt
acting in threaded portions adjoining the ends of the parts of the rings.
GB 2 193 605A discloses a cable joint comprising a two part hollow sleeve
and two end caps which can be clamped together by a clamping ring at each end.
The
clamping ring is in two parts hinged together with the ends remote from the
hinge
being provided with threaded portions which enable them to be brought together
by
means of a bolt.
Cable splice closures, for example for optical fibre cables, in which a base
and
a cover are fastened together by means of a clamp, e.g. a split ring clamp,
which is
closed in its clamping position by means of an over-centre closing device are
commercially available.
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A problem with conventional clamps is that it is often difficult for an
engineer
in the field to close a clamp around a cable splice closure housing,
particularly when
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the clamp and/or the housing is/are new. Often the engineer
has to resort to hitting the clamp with a hammer or a mallet
(which may damage the housing and/or the cables, and
generally makes installation difficult) in order to close it
sufficiently so that the lever of the over-centre closing
device of the clamp can be operated to close the clamp
fully. It would therefore be desirable to make the initial
stage of closing the clamp easier.
It is often necessary to re-open cable splice
closure housings in order to gain access to the cable
splices. Conventional cable splice closure clamps often
suffer from the problem that they are difficult to remove
from the housing of the closure once they have been closed,
particularly when they have been closed for some time. At
present, the engineer who opens a housing often has to use a
separate tool (which, at least in some cases is a specially
designed tool) to help him to open the clamp and remove it
from the housing. It would be desirable to remove the need
for the use of such tools.
According to the invention there is provided an
article comprising first and second parts, which can be
closed together, and an over-centre device for effecting
said closure, the over-centre device comprising a lever
pivotally attached to an arm which is pivotally mounted to
the first part of the article, the lever having an
engagement surface at a free end of the lever which engages
the second part of the article and fastens the two parts of
the article together when the lever is in its over-centre
position in use, characterised in that the lever has an
extension piece which extends, seen along the length of the

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lever, beyond the engagement surface at the said free end of
the lever, and which is arranged to cooperate with the
second part of the article to provide an initial closing
leverage during an initial stage of closing the article, and
which allows the engagement surface to contact the second
part of the article to provide final closing leverage during
a final stage of closing the article.
The invention has the advantage that because the
lever has an extension which may cooperate with the second
part of the article (the article may, for example, comprise
a clamp, or a housing itself) to provide initial closing
leverage during an initial stage of closing the article,
this initial stage of closing the article is made easier and
normally avoids the necessity of hitting the clamp, thereby
solving the first problem mentioned above.
In a preferred embodiment of the invention, the
extension piece on the lever is arranged so that when the
first and second parts of the article are closed, it can
cooperate with the second part of the article to provide an
initial opening leverage during an initial stage of opening
the article. This preferred embodiment of the invention has
the advantage that because the lever has an extension piece
which extends beyond the engagement surface and which may
cooperate with the second part of the article to provide an
initial opening leverage during an initial stage of opening
the article, the necessity of using a separate tool to
facilitate opening of the clamp is avoided, thereby solving
the second problem mentioned above. Advantageously, the
leverage provided by the closing device of the invention
provides at least some radially outward movement of the

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clamp, e.g. radially away from a housing around which it is
positioned. This normally enhances the ease with which the
clamp may be opened and removed, and is particularly
difficult to achieve without the extension piece of the
lever according to the invention.
Preferably the first and second aspects of the
invention are combined in a single over-centre closing
device.
Preferably the second part of the article has a
protrusion, and the cooperation of the extension of the
lever with the second part of the article comprises contact
between the extension and the protrusion. Advantageously,
the extension may have a

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hook-like part which engages the protrusion during the cooperation of the
extension
with the protrusion.
The article may comprise a housing, preferably a cable splice closure housing.
Preferably, however, the article comprises a clamp, especially a clamp in the
form of a
split ring. The split ring may be non-circular, e.g. oval or angular, but
normally it will
be substantially circular when closed. The split ring is preferably hinged to
enable it
to be opened, placed around a housing etc., and closed in place. The invention
may
consequently provide a clamp for fastening together first and second parts of
a
housing, comprising a split ring and an over-centre closing device according
to the
invention, the split ring comprising the article and the over-centre closing
device
closing the split ring in a clamping position in use. The housing preferably
comprises
a cable splice closure housing. The clamp preferably fastens together
peripheral
flanges on the first and second parts of the housing. The clamp is preferably
provided
with means, e.g. angled portions, which cooperate with corresponding portions,
e.g.
flanges, on the parts to be clamped so that closing of the clamp urges the
parts
together.
Preferably a pair of extensions are provided on the lever, each of which
preferably cooperates with a protrusion on the second part of the article
(e.g. clamp).
The invention will now be described, by way of example, with reference to the
accompanying drawings, in which:
Figure 1 is a perspective view of a clamp according to the invention prior to
the initial stage of closing.
Figure 2 is a perspective view of the clamp of Figure 1 in the closed position

prior to the initial stage of opening.
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Figure 3 is an enlarged view of the clamp of Figure 2, showing the closing
device in detail.
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Figure 4 is an enlarged view of the clamp of figures 1 to 3 subsequent to the
initial stage of opening.
Figure 1 is a perspective view of part of a clamp 1 according to the
invention.
The clamp comprises a split ring (e.g. for closing around peripheral flanges
of a cable
splice closure housing) having a first part 2 and a second part 3 (the entire
clamp is
shown in Figure 2). The closing device 6 of the clamp 1 comprises a lever 11
pivotally attached at 12 to an arm 9 which is pivotally mounted at 20 to the
first part 2
of the clamp. The lever 11 has an engagement surface 21 which engages the
second
part 3 of the clamp at 8 and fastens the two parts 2, 3 of the clamp together
when the
lever is in its over-centre position in use (which is shown in dotted lines in
Figure 2).
The lever has two extensions 15 which extend beyond the engagement surface 8
and
which, as shown in Figure 1, may cooperate with the second part 3 of the clamp
by
contacting protrusions 17 (which are preferably in the form of pins) to
provide initial
closing leverage during an initial stage of closing the clamp. In this mode of
operation therefore, the extensions 15 increase the stroke of the lever 11 in
comparison to conventional levers without such extensions. Although, in this
mode
of operation, the amount of leverage provided by the lever is reduced due to
the use of
the extensions, it is normally sufficient for this initial stage of closing
the clamp. In
conventional closing devices, this help during the initial stage of closing
the clamp is
not provided due to the absence of such extensions, and consequently closing
the
clamp sufficiently to enable the closing device to close the clamp fully may
be
difficult.
1
Figure 2 shows the clamp 1 of Figure in its closed position. The whole of the
clamp is shown, and a hinge 4 between parts 2 and 3 is illustrated. The final
over-
centre position of the lever 11 is shown in dotted outline, and the fully
drawn lever is
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shown prior to its use as an initial opening leverage during an initial stage
of opening
the clamp. The closing device 6, including the lever 11, is shown in greater
detail in
Figure 3. Hook-like parts 16 on the end of extensions 15 are shown engaged
with
protrusions 17. In Figure 4, the lever 11 has been used to provide an initial
opening
leverage to open the split ring clamp, via the engagement of the extensions 15
with the
protrusions 15. Preferably this leverage imparts at least some radially
outward force
to the clamp which helps to release it from the housing. Thus figures 2 to 4
illustrate
the second advantageous feature of the invention, namely making the opening
and
removal of the clamp easier than is the case with conventional clamps.
Conventionally a separate tool is normally needed in order to enable the clamp
to be
opened. The invention removes the need for this separate tool and provides a
simple
and effective mechanism for opening the clamp.
The clamp, and particularly the closing device, shown in figures 1 to 4
illustrate how both advantageous features of the invention (i.e. ease of
closing the
clamp and ease of opening the clamp) may be combined in a single embodiment.
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Representative Drawing