Storage arrangements for optical fiber connections

Storage arrangement for optical fiber connections in which a storage enclosure for storage trays has tray storage mounts and a tray securing means is resiliently flexibly operable to allow for insertion and removal of trays. Particularly, ends of trays have two arms of a bifurcated structure, the arms being resiliently flexible towards one another. A tray mount is a slot which accommodates two arms at one end of a tray and a locking pin holds the arms apart in the assembled position.

This invention relates to storage arrangements for optical fiber 
connections. 
It is necessary in the use of optical cables to provide connections between 
fibers of one cable and those of another, for instance, when connecting 
together lengths of cable or when connecting a branch cable into a main 
cable. Optical fiber connectors are used for this purpose. Such connectors 
and lengths of optical fibers bared of surrounding cable material in the 
regions of fiber connections are housed within storage enclosures. These 
enclosures house a plurality of storage trays each of which has a guide 
and a retaining function whereby connectors and bared optical fibers are 
retained in fixed stored positions so as to prevent signal attenuation 
problems along the bared fibers. These trays are stacked closely together 
within the storage facility into which cables extend with ends of the 
storage facility secured onto the cable sheaths. A problem which exists 
with such storage facilities is the lack of availability and difficulty in 
removal of selected trays. In present designs of storage facilities, all 
of the trays need to be removed from an enclosure and the stack of trays 
needs to be partially dismantled to reach a selected tray and separate it 
from other trays to enable an engineer to work on connectors associated 
with the selected tray. 
The present invention seeks to provide a storage arrangement wherein the 
above problem is minimized or avoided. 
According to the present invention there is provided a storage arrangement 
for optical fiber connections which comprises: (a) a tray storage 
enclosure for housing a plurality of storage trays for storing optical 
fiber connectors and lengths of fiber joined to and extending from the 
connectors, the enclosure having an enclosure body and a cover sealingly 
attachable to the body to define an enclosure chamber; (b) at least two 
tray mounts locatable in spaced positions within the enclosure chamber; 
(c) a plurality of storage trays for location within the chamber and 
between the tray mounts; and (d) tray securing means defined partly by 
each tray and partly by each mount for individually detachably securing 
each tray between and to the tray mounts by a resiliently flexible 
operation of the securing means. 
More particularly the present invention provides a storage arrangement for 
optical fiber connections which comprises: (a) a tray storage enclosure 
for housing a plurality of storage trays for storing optical fiber 
connectors and lengths of fiber joined to and extending from the 
connectors, the enclosure having an enclosure body and a cover sealingly 
attachable to the body to define an enclosure chamber; (b) at least two 
tray mounts locatable in spaced positions within the enclosure chamber; 
(c) a plurality of storage trays for location within the chamber and 
between the tray mounts; and (d) tray securing means comprising resilient 
extensions at ends of the trays and extension receiving slots formed in 
surfaces of each mount, each said surface facing outwardly of the body 
with the cover removed, the resilient extensions being movable into and 
out of the slots when in resiliently flexed conditions and being 
retainable in the slots in more relaxed conditions. 
In a preferred arrangement, each mount defines a slot which is narrower at 
a top region than in regions below the top region. The resilient 
extensions are resiliently flexible to pass downwardly through the top 
regions of the slots but in more relaxed conditions, the extensions have a 
width greater than the narrow top regions of the slots. 
Advantageously in a preferred arrangement, each resilient extension is 
bifurcated with two arms which in normal relaxed conditions are spaced 
apart. Resilient flexing of each extension causes the arms to approach one 
another to reduce their overall width. 
It is advantageous to have a locking means to retain the extensions within 
the recesses so as to prevent any accidental removal of the extensions. 
The locking means is conveniently provided by a locking pin which is 
receivable between opposing surfaces of each extension, these opposing 
surfaces formed with opposing recesses for the purpose of receiving the 
pin when the overall width of the arms is greater than the narrow top 
region of a slot.

As shown by FIG. 1, a storage arrangement of the embodiment comprises a 
storage enclosure 10 basically of conventional construction. Briefly, the 
enclosure comprises an elongate enclosure body 12 and a cover 14. The body 
12 has opposing sides 16, ends 18 and a bottom 20 and planar flanges 22 at 
the top ends of the sides 16. The cover 14 is formed similarly to the body 
12, but is inverted onto the body when assembled to it as shown by FIG. 1. 
Flanges 24 of the cover 14 mate with the flanges 22 and an edge seal 26 is 
located between the flanges to seal a chamber 28 from ambient atmosphere. 
At the ends of the body 12 and cover 14 are provided extensions 30 which 
mate together to enclose resilient cable sealing pads 32 having apertures 
34 formed therein for sealing engagement around cables passing into the 
chamber 28. The sealing pads form part of a composite sealing member in 
assembly with edge seals 26. 
The chamber 28 is for containing a plurality of side-by-side located 
storage trays for storing optical fiber connectors and lengths of fibers 
joined to and extending from the connectors. As shown by FIG. 2, the body 
12 carries two tray mounts 36 spaced apart along the length of the body, 
the tray mounts in turn carrying a plurality of storage trays 38. For 
clarity, only one storage tray 38 is shown. 
As shown more particularly by FIG. 3, each tray mount 36 is in the form of 
a flat plate. This is provided with means for location of each plate 
within the storage enclosure. This means comprises two end projections 40 
lying in the plane of the plate, the projections lying in a top region of 
the plate when this is in a vertical condition as mounted in the storage 
enclosures. As can be seen from FIG. 3, each mount is lowered into the 
body 12 to enable its end projections 40 to be received within recesses 42 
formed at the junction of the sides 16 and the flanges 22. FIG. 1 more 
clearly shows these recesses which are arranged in opposing pairs across 
the chamber 28. There may be more than one pair of recesses at each end of 
the chamber, as shown in FIG. 1, to vary the spacing between the mounts to 
accommodate various lengths of trays. It will be appreciated that with the 
cover 14 located in position the flanges 24 of the cover overlie the top 
surfaces of the projections 40 so as to fix the mounts 36 in their desired 
positions within the chamber 28. 
The trays 38 are basically of conventional construction except for ends of 
the trays which provide part of a tray securing means for detachably 
holding the trays to the mounts 36. The tray securing means comprises 
resilient extensions 44 (FIG. 4) lying in the planes of the trays at the 
tray ends and extension receiving slots 46 formed in edge surfaces of the 
mounts which face upwardly and outwardly of the body with the cover 
removed. As can be seen from FIGS. 3, 4, 5 and 6, each of the slots 46 is 
provided by upwardly extending webs 48 on the upper edge surface of each 
mount, the webs spaced apart to define the slots between them. The webs 
are T-shaped in end view so as to have upper outer end portions 50 which 
are of greater width than the remainder of the webs. Hence top regions of 
the slots between the end portions 50 of the webs are narrower than other 
and lower regions of the slots. 
Each of the tray extensions 44 is bifurcated such that it is formed with 
two horizontally spaced apart arms 52 which are resiliently flexible 
inwardly, i.e. towards each other. In the relaxed conditions of the arms 
52, the total width across the arms is greater than the width between 
adjacent end portions 50 of the webs and may also be greater than the 
width of the slots below the web portions. The arms may be flexed 
resiliently inwards whereby their reduced total width is less than the 
distance between the slots 50 so as to enable the resilient extensions to 
be passed downwardly between the webs and into the slots. 
The storage arrangement is also provided with a locking means for holding 
the two arms apart so as to prevent them from being inadvertently flexed 
towards each other as such movement could result in removal of a tray from 
within the chamber 28. This locking means comprises a locking pin 54 which 
is insertable downwardly between opposing recesses 56 formed in opposing 
surfaces of the two arms, the recesses having dimensions such as to accept 
the locking pin in the spaced apart condition of the arms. 
To assemble the trays into the storage enclosure, the two tray mounts are 
located in position in the enclosure body, as shown in FIG. 2. Each tray 
in turn is located in a vertical plane and then is lowered with its two 
extensions 44 in alignment with aligned recesses in the mounts at the two 
ends of the chamber 28. This position for one mount is shown in FIG. 4. To 
locate each tray in a fixed position within the body, the arms 52 at each 
end of the tray are resiliently flexed inwards to reduce their overall 
width and the tray is moved downwardly by passage of the arms between the 
end portions 50 of the webs 48. This position is shown in FIG. 5. After 
the arms have passed downwardly beyond the end portions 50, they are 
released whereby they return towards their normal unstressed conditions, 
i.e. they move further apart, until they engage the opposing faces of the 
webs 48. The recesses 56 are then spaced sufficiently far apart to accept 
the pins 54 which are inserted between the recesses to prevent the arms 
from moving together unless required. This position is shown in FIG. 6. 
As can be seen from the above description, the trays are located in this 
fashion vertically side-by-side within the chamber 28. If it should be 
required to remove any one tray from the chamber for connection of optical 
fiber ends of cables 58 (FIG. 2) extending into the enclosure and for 
holding connectors between the cables, then removal of a single selected 
tray is a simple process. As can be seen from FIGS. 5 and 6, the arms 52 
of a tray are sufficiently long to extend right through a corresponding 
slot 46 and project from the other side. To remove the tray, the pins 54 
at its two ends are removed, possibly by the use of gripping pliers. The 
projecting ends of the arms 52 are then urged together so as to reduce the 
overall width of each projection 44 whereby the tray may be removed 
vertically with the arms passing between the end portions 50 of the webs. 
As can be seen, therefore, removal of a single tray for connection or 
maintenance purposes is a simple operation and is not hampered by the 
location of other trays. Furthermore, removal of a single tray for each 
operation avoids the possibility of having a large number of removed trays 
lying loosely around the enclosure with their accompanying lengths of 
optical fiber and connectors.