Note: Descriptions are shown in the official language in which they were submitted.
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MOVABLE CLOSURE FOR OPTICAL ELEMENTS
1 FIELD OF THE INVENTION:
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This invention relates to closures for optical
element terminations, and more particularly to the
removable closure of the end of an optical fiber in an
optical fiber connection.
BACKGROUND OF THE INVENTION:
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In the coupling of optical elements, an end
face thereof is typically exposed so as Jo be coupled
with an end face of a second optical element. In
particular with optical fiber connectors, such end faces
are commonly formed by cleaving the ends of the optical
elements. In the ultimate connection of the elements a
protective sleeve forming a portion of the connector is
often provided, such sleeve insulating and protecting the
fibers prom exposure to the environment However, when
the connectors are no-t mated, e.g., prior to actual
connection or when a change in connection is desired, the
cleaved ends are usually exposed. Foreign matter such as
dir-t, dust or the like can enter the connector, covering
or at least partially blocking the end face of optical
fiber. This blockage can severely affect the optical
transmission capabilities of the connector.
Prior attempts have been made -to provide a cover
or cap for optical fiber ends for use in a wide variety
of applications. These prior devices include shutter-type
mechanisms which are activated by external means. While
such shutter-type mechanisms effectively serve to block
optical transmission between end-to-end optical elements
they provide little protection from outside particles and
contaminants. Further, these prior devices are actuated
in a separate step apart from that of the connection of
the elements. This results in exposure of the optical
element prior to connection.
Accordingly, the prior devices, while providing
an end cover or shutter for cutting off optical transmission,
do not sufficiently cover the end of the fiber so as to
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protect i-t from outside contaminants and debris. Further,
these known devices do not enrage automatically upon disk
connection of the optical elements.
SUMMERY OF THE INVENTION:
It is an object o-f the present invention to
provide an improved closure for optical element terminations.
It is a further, more particular object to
provide a closure for the cleaved end of an optical fiber in a
connector, which closes upon disconnection.
These and other objects and features are
found in the present invention which looks toward providing a
closure for optical element terminations, more particularly in
a resilient shroud for an elongate optical fiber connector house
in. The shroud is mounted to the connector housing and is
resiliently movable between two positions: a first position
wherein the shroud blocks or covers the optical fiber end; and
a second position wherein the shroud uncovers the optical fiber
end. The shroud has an engagement portion adjacent an axial bore
of the housing, adapted to be engaged upon connection of the
housing with another optical element. The shroud movement is
responsive to the engagement ox the engagement portion. The
position of the shroud is such that when the connector is connect-
Ed to a second optical element, say another connector, the fiber
end is uncovered for complete optical transmission. Upon disk
engagement, the shroud moves to a position covering the fiber
end, not only blocking optical transmission, but also shielding
the fiber end from outside con~aminents.
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Further embodiments of the shroud are contemplated,
including a shroud having an aperture. In covered position -the
aperture is in non alignment with the fixer end and in uncover
Ed position, the fiber end and aperture are aligned.
Other objects and features of the invention will
be evident from the following detailed description of -the
accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWING:
Figure 1 is a longitudinal cross-sectional view
of an optical cable connector, including the shroud of the
present invention shown in the normally-covering position.
Figure 2 is a partially fragmented view of the
Figure 1 connector shown connected to pa further optical element
housing with the shroud in the open position.
Figure 3 is a longitudinal cross-sectional view
of an optical cable connector including another embodiment
of the shroud of the present invention) such shroud being
shown in covering position.
Figure 4 shows a partially fragmented view of
the connector of Fig. 3 being connected to a further optical
element housing, -the shroud being shown in the open position.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS:
Referring to Fig. l, there is shown an optical fiber
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cable connector 20, useful in securing the terminal end of an
optical cable 10 for connection with a similar end of a second
optical cable, held in a mating connector, not shown.
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Cable connectors are disclosed as being preferred examples of practicing the present invention. Notwithstanding
the preferred environment, the invention disclosed herein is
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not limited four use with the presently disclosed connector
or with any conventional connectors alone, but may be employed
Wyeth various optical element termination devices. For
simplification of description and ease in understanding, the
present invention is being described in connection with fiber
optic cable connectors such as the type shown and described in
Canadian Patent No. 1,149,654 issued July 12, 1983 and assign-
Ed to -the assignee of the instant application.
Connector 20 is a fiber optic cable connector
which terminates a conventional cable 10 including optical
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l Eyebrow Lo or connectiorl with a secor1cl optical fiber. Thy
connector 20 includes an outer housing on which keynote
a retainer ring 22, and a surrounding ferrule 18 or accomtno--
dating the cable and fiber. An end cap 24 secures the
retaining ring and ferrule yin place in the housing. A
fiber guide 44, also contained in housing 30, accepts the
extending fiber 12, securing relative longitudinal
orientation. The fiber guide 44 is spring-loaded under
the bias ox spring 46 situated between fiber guide 44
and retaining ring 22, so as to permit exposure of the
fiber end face if through end aperture aye. An internally
screw-threaded coupler 34 is rotatable secured to the
housing/ longitudinally projecting therefrom to form a
female receptacle for a second connector-type termination
lo (not shown). Ring 38 secures coupler 34 in a fixed
rotative position.
In preferable form, the longitudinal extent
(tip 44b~ of giber guide 44 is tapered and tenants at
aperture aye. This permits fiber guide 44 to serve as
an insertion-type element to project fiber end face if
into the desired mating connector.
In accordance with the invention, sl.idahly
secured -to the outer surface of giber guide 44 is shroud
50. The shroud 50 is formed of strong, resilient material,
preferably beryllium copper or other suitable material
that is ~ormea to the shape of the tapered tip 44b of fiber
guide 44. In order to conform more readily to the shape
of the tapered tip 44b, shroud 50 may be slightly arcuate
along its transverse axis. Shroud 50 is secured to the
housing so as to have a positional bias. For example,
the shroud 50 may be mounted by a spring 53 which would
position the shroud normally, as shown in Fig. l, wherein
the outer edge 51 extends over and covers aperture aye,
across -the transverse extent of liken guide 44. It is
contemplated that any well-known biasing means may be
employed, spring biasing being disclosed only by way of
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1 example. A further example would be to form shroud 50 of
material having natural biasing tendencies so that the
shroud would resiliently recover to the position shown in
Fig. 1 upon removal of external forces.
The inner extent (oppositely directed from the
outer edge 51) of shroud 50 includes an upwardly depending
shoulder 52 which is constructed to abut -the outer extent
of a second connector housing as described hereinafter.
Fig. 2 shows the connector of Fig. 1 engaged
with and connected to a second optical housing. In the
present example, central housing 60 is shown, which can
be any simple connector-type termination apparatus or
connecting two optical fibers.
Central housing 60 includes a central opening
lo aye defining an outer annular surface 61 for insertion
into the female receptacle formed by coupler 34. Central
opening 61 thereby accepts fiber guide 44. The external
edge of central housing 60 is screw-threaded for screw-
type connection with internally threaded coupler 34 of
housing 20.
Having herein described the structure of the
present invention, its operation will now be described.
With shroud member 50 in its normal position so
that outer edge 51 closes aperture aye of fiber guide 44,
central housing 60 may be inserted into the chamber defined
by the coupler 34. Rotation of coupler 34 will force
central housing 60 inwardly due to the threaded relation
between the members. This inward movement will force
outer annular surface 61 to abut shoulder 52 of shroud 50.
Further rotation of coupler 34 will impart further inward
movement of central sousing 60, thereby driving in
shoulder 52 and moving shroud 50 from its normal position
to a position as shown in Fig. 2, wherein aperture aye is
now exposed. Fiber 12 now is in the connected position.
As can be seen, aperture aye will remain covered
and protected by shroud 50 until ultimate connection takes
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1 place. Similarly, upon disconnection, by removal of central
housing 60 from coupler 34 and thereby removing the
resistance to the biasing tendencies ox shroud 50, Shari
50 will return to its normal position covering aperture aye
under the influence of the spring bias 53.
Fig. 3 shows an alternative embodiment of the
present invention. The connector, fiber guide, housing etc.,
are all substantially similar to those described with
reference to Figs. 1 and 2. For simplification of
description, with respect to Figs 3 and 4, those elements
'naming similar characteristics will be denoted by similar
reference numerals by the addition of 100 to the reference
numerals of Figs. 1 and 2. As an example, fiber guide 144
of Figs. 3 and 4 is similar to Fiber guide I of Figs. 1
and 2.
Shroud member 150 in accordance with this
embodiment of the invention as shown in Fig. 3, is
substantially Shaped having a longitudinal portion 153
and a transverse portion 157 extending from the outer edge
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1 and 2, shroud 150 can be arcuate across its transverse
length so as to conform to fiber guide 1440 Centrally
located in transverse portion 157 is an aperture aye,
having an opening which is at least as large as aperture
aye of fiber guide 144.
Shroud 150 is pivotal secured at its longitu-
dial edge opposite from the transverse portion to the
outer surface of fiber guide 144. The longitudinal portion
153 extends substantially along the length of the fiber
guide 144 and transverse portion 157 extends transversely
across tip 144b. Shroud Cowan be attached to the outer
surface of fiber guide 144 by any well known Sacramento
means, such as, for example, a spot weld, or solder.
In order to provide the resilient qualities
desired, shroud 150 it constructed of material which is
known to have natural longitudinal resilience, or the
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assess
I ability to recover its original shape after external
Russ it released. As an example, a material such us
beryllium copper can be employed which, after being flexed
about the pivot point, will return -to its original position.
In normal position, shroud 150 is positioned so
that the longitudinal member 153 secured at pivot point
aye extends up at an angle as measured from the
longitudinal axis of fiber guide 144. Transverse member
157 will then extend down so that the lower edge aye will
cover aperture aye of fiber guide 144. Thus, aperture
aye and aperture aye will be non-aligned.
Fig. 4 shows connector 120 connected to central
housing 160. Shroud 150, urged downward by central housing
160 is in open position with aperture aye being aligned
with aperture aye.
With reference to Figs 3 and 4, the present
modification operates as follows:
Shroud 150 being in normal position as above
described, is engaged by the central housing 160 to be
connected. The inside wall of central housing 160 abuts
- the longitudinal extent of shroud 150 and urges the shroud
downwardly against the fiber guide 144 upon inward movement
of the central housing r occasioned by rotation of coupler
134. When the central housing has been tightly connected
to the connector 120, longitudinal portion 153 of shroud
150 will lie relatively flat along the outer surface of
fiber guide 144. The corresponding movement of transverse
member 157 will cause alignment of aperture aye and
aperture aye, exposing optical fiber 112 for connection.
Similarly, upon disconnection, ire., removing
the central housing 160, which is holding shroud 150
against fiber guide 144, the resilient tendencies of
shroud 150 will return it to its normal position, thereby
covering aperture aye as it is no longer aligned with
aperture aye.
The particularly described embodiments are
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1 disclosed by way of example and illustration and are trot
intended to limit the scope of the invention. The scope
of the invention is set forth in the appending claims.
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