Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
08~437
This invention relates to apparatus for use in
fluidized powder filling of multiple core unit cables, and is
particularly concerned with opening means for opening a cable
into the individual core units for filling.
In copending Canadian application no. 306,402
filed 28 June 78 in the name of the present assignee there is
described the fluidized powder filling of a cable core by passing
the cable core through a fluidized bed in a substantially closed
condition. There appears to be a limit to the size of cable core
which can effectively be filled, and in the case of a telecommunica-
tions cable having a core composed of a multiplicity of pairs of
conductors, a convenient maximum unit size is fifty pairs of
conductors.
For cables having more than this number of conductors,
the cable core is "opened" to form a number of core units, each unit
being in a substantially closed condition as it passes through the
fluidized bed. The cable core can be opened before or after
entering the fluidized bed, and closes back again in the bed.
In its broadest aspect, the invention is concerned
with an opening device for opening a cable core into a plurality
of core units, with the individual units being powder filled in a
substantially closed condition. The opening device can be positioned
in the fluidized bed or outside the bed prior to passage of the
cable core through the bed. The device comprises an opening member
freely riding on the cable core and supported against a support
member through an air bearing arrangement.
The invention will be readily understood by the
following description of certain embodiments, by way of example,
in conjunction with the accompanying drawings, in which:-
Figure 1 is a diagrammatic longitudinal cross-
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section through a filling bed with an opening device in the bed;
Figure 2 is a diagrammatic perspective view of
the two basic parts of the device, shown spaced apart for clarity;
Figure 3 is a cross-section on the line III-III
of Figure 2, with the device as in use;
Figure 4 is a diagrammatic longitudinal cross-
section through a filling bed with an opening device outside the
bed, before entry of the cable core;
Figure 5 is a front view of the opening device in
Figure 4, as it would be seen in the direction of the arrow A
in Figure 4;
Figure 6 is a cross-section on the line VI-VI
of Figure 5, illustrating the opening device in more detail;
Figure 7 is a perspective view on the inner face
of the inlet wall of the bed, showing an air collector.
As illustrated in Figure 1, a fluidized powder
filling bed is indicated generally at 10, the powder being in ;-
the main portion 11 having a perforated base member 12, an air
box 13 under the member 12, with an air supply at 14. The main
portion is covered by a lid 15 and dust extraction is provided
at 16. The bed can be supplied with powder either by removing the
lid or by providing an inlet. A typical form of bed is illustrated
- in the above mentioned application.
A cable core 17 enters via an inlet die 18 and then
~i~ the core is opened by the core units passing through an opening
device 19. After passage through the opening device the core
units close together, as indicated at 20, and then exit through
an exit die 21. After passing through the exit die the core can be
wrapped, for example by a tape wrapping-device 22 and tape 23.
The opening device can be supported in the bed by a support plate
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24 extending across the main portion 11.
The opening device 19 is illustrated in more
detail in Figures 2 and 3. The device comprises a support member
25 attached to the support plate 24, and an opening member 26
which rides on the cable core 17, the core opens up into a
plurality of core units 27. Support member 25 is annular in form
and has an annular passage 28 formed from the back surface. The
back surface of the support member is held tight against the
support plate 24, as by screws at 29, and pressurized air if fed to
the passage 28 via an inlet 30. Formed in the front face of the
support member 25 are a number of small orifices 31 communicating
with the passage 28. In operation, with the opening member 26
riding on the cable core, the drag on the opening member holds it
against thè support member 25, and the opening member is also
maintained in alignment with the support member. High pressure
air feeds through the orifices 31 and supports the opening
member 26 a short distance away from the support member, allowing
virtually friction free relative movement. The air also prevents
fluidized powder penetrating between the two members. Holes 32
are formed through the opening member 26 for passage of core units
therethrough.
To start the operation, the cable core is divided ~--
into the required number of core units after passage through the
inlet die 18. While seven are shown in Figures 2 and 3, a smaller
number can occur, or a larger number. For large cable cores more
than one row of holes 32 can be provided in the opening member.
The individual core units are then put through the holes 32, then
through the centre of the support member 25 and then out through
the exit die 21. Usually a pulling member is attached to the end
of the cable core to lead it through any successive stages and on
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to the take-up spool. The bed is then closed, air admitted to
the air box 13 and the powder fluidized. The cable core is pulled
through the bed, the core opening to pass through the opening
member 26 and then closing again. The powder fills the interstices
between the conductors in each core unit prior to the cable core
closing together. There is some twist in the core units, about
the longitudinal axis of the core, and the opening member 26, which
is freely rotatable upon the support member 25, can rotate relative
to the support member quite easily.
Figure 4 illustrates diagrammatically an alternative
arrangement in which the opening device 19 is mounted on the outside
of the bed 10 at the inlet to the filling portion 11. Where
applicable the same reference numerals are used in Figure 4, and in
Figures 5 and 6, for the same items as in Figures 1 to 3. The cable
core is opened into units before entering the fluidized bed, closing
again in the bed, at 20.
Figures 5 and 6 illustrate in more detail the opening
device 19 of Figure 4. In this example a support member 40 is attached ~ :
to the inlet end wall 41 of the main portion 11 of the bed. The support
member 40 is tubular and has a conical support surface 42 and an
annular wall ~3 extending in a direction away from the inlet end wall
and projecting from the outer periphery of the conical surface to form
a chamber. An annular channel 44 is formed in the back of the support
member and pressurized air is supplied to this channel via an inlet 45
connecting passage 46. Small orifices 47 extend from the support
surface 42 through to the channel 44.
Positioned within the chamber of the support member 40
is an opening member 50. The opening member has a forward, conical
surface 51 which is in opposition to surface 42. The periphery of
the opening member is also a freely moveable fit inside the wall 43.
An annular chamber 52 is formed in the periphery of the opening member
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and pressurized air is fed to this chamber via an inlet 53. From
the chamber 52 air is fed via small diameter bores 54 to holes
55 and 55a extending through the opening member and through which
pass the core units. The feature of the air supply bores 54 will
be described later.
The rearward surface 56 of the opening member 50
is recessed around the periphery to provide a rearward bearing
surface 57, and a retaining member 58 is positioned in the recess.
The retaining member has a radially extending flange 59 which mates
with a radially extending flange 60 on the support member 40 and
screws 61 connect the two flanges together. A gasket 62 can be
positioned between the flanges. The retaining member has an
annular cavity 63, closed by a cover plate 64 with a gasket 65.
Small orifices 66 connect the cavity 63 with the front surface 67
of the retaining member. Pressùrized air is fed to the cavity
63 via an inlet, not shown.
In operation, once the cable core has been
initially opened and the core units passed through the holes 55,
and 55a through the bed 10, out through the unit die 21 and on to
the take up spool, air is supplied to the air box 13 to fluidize
the powder and also to the channel 44, chamber 52 and cavity 63.
The pressurized air fed to the channel 44 and
cavity 63 flows through the orifices 47 and 66 and forms an air
bearing between the support member and the opening member. There
is thus virtually no friction between support member and opening
member. Air will also flow between the outer periphe~ry~bf~tbe
opening member and the inner surface of the wall 43.
Although the core units are passing through the
holes 55 and 55a at a fairly high speed, say over 100 ft. per
minute, powder tends to escape from the bed out through the holes.
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By feeding air in via inlet 53, chamber 52 and bores 54, a small
net flow of air into the bed can be achieved, preventing outflow
of powder. The flow of this air can be controlled so that powder
leakage is just prevented. The air flowing from the orifice 47
between conical surfaces 42 and 51 flows out from between these
surfaces at the mounting position on the end wall 41. This flow
could interfere with the fluidized bed and a collection system can
be provided. As seen in Figures 6 and 7, collector member 68 is
attached to the inside of the wall 41, the inner periphery of the
10 member 68 situated in a recess 69 in the forward end of the
opening member. The inner portion of the member 68 is recessed
on the side facing the support member 40 and opening member 50 and ~-
forms an annular conduit 70 into which the air flows from between
surfaces 42 and 51. The annular conduit 70 connects via a passage
71 to an outlet 72 opening into the space above the ib~d at 11.
The bed exhaust is slightly below atmosphere pressure. Similarly,
an air supply can be provided to feed air to the holes 32 in the
opening member of Figures 1, 2 and 3.
Thus the opening member 50 rides freely on the
20 cable core and can rotate freely within the support member as the
cable core passes through the bed. The number of holes 55 can vary
depending upon core size and number of core units. More than one
row of holes 55 can be provided, as necessary. It is also possible
to provide an opening member with a large number of holes 55, with
means for blocking those holes not used.
As a typical example, the bed 10 can be 4 ft. long.
The cable core units close down at a position which can vary from
about 6" to about 18" from the inlet wall. The larger the cable
the greater the distance the closing down from the inlet. The
30 bed can be made shorter, but the size given will accommodate various
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cable sizes. It is believed that the length of bed beyond the
closing down of the core units evens out the filling, but the
majority of the filling occurs at the beginning before the core
units close down. A typical air supply pressure is about 80 psi
although this can vary and lower pressures have been used. The
air flows are quite small. The size of the holes 32 and 55 will
depend upon the size of the cable core units passing therethrough.
As an example, for the arrangement as illustrated in Figures 5 and
6, the following table gives typical dimensions for a telecommuni-
10 cations cable, in which the cable core has been divided up sothat core units of alternately twelve and thirteen pairs pass
through holes 55, and a twenty-five pair unit passes through
hole 55a. Other numbers of pairs per unit can be provided with
corresponding adjustment to the hole diameters.
Wire Holes Hole
Gauge 55 55a
24 .358" dia. .468" dia.
22 .397" dia. .515" dia.
26 .316" dia. .406" dia. ~ -:
, 19 .531" dia. .703" dia.
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SUPPLEMENTARY DISCLOSURE
Figure 8 is a cross-section through an alternative
form of cable opening device, on the line VIII-~III of Figure 9, - -
Ffgure 9 is a face view in the direction of arrow A
in Figure 8, with certain hidden details shown in dotted outline-,
Figure 10 is a partial cross-section, on the line
X-X of Figure 8, illustrating the structure at the periphery of
the rotating member.
The arrangement illustrated in Figure 8 is for a large
cable, the arrangement opening the cable into 18 units. The arrange-
ment comprises an opening member or rotor 80 having eighteen axially
` extending holes 81 extending therethrough. The rotor is supported in
a support member or housing, indicated generally at 82, and has a
central portion 83 of larger diameter than end portions 84 and 85.
The housing 82 has a central portion 86 and end portions 87 and 88, the
inner bores of the portions 86, 87 and 88 being such that the rotor is a
close rotating fit therein.
Inset into the central portion 86 of the housing 82
are a plurality of nozzle units 89 and a plurality of exhaust outlets
9o, In the particular example illustrated there are four nozzle units
89 spaced 90 apart round the central portion 86, and four exhaust
outlets 90 also spaced 90 apart and being midway between the nozzle units.
Air is supplied to the nozzle units 89 via pipes, not shown,
connected to threaded inlets 91, and exhaust air is exhausted through
pipes, not shown, connected to threaded outlets 99. The four nozzle
units 89 and four exhaust outlets 90 are shown in dotted outline in
Figure 9.
Positioned in each nozzle unit 89 is a nozzle member 92,
illustrated in cross-section in Figure 10. The periphery of the central
portion 83 of the rotor 80 has a plurality of semi-circular grooves 93
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in alignment with the nozzle members 92. A circumferential groove 94 ~ :
extends on either side of the grooves 93. The grooves 93, with the - -
nozzle members 92, form an air turbine structure. Air admitted to a
nozzle unit 89 is ejected by the nozzle member to impinge on the grooves ~ .93 to produce a rotational effort on the rotor 80. The nozzle units 89
are mounted in circular housings 95 welded to the housing 82. The
nozzle units can be inserted in the housings in one of two directions, .-
either as illustrated in Figure lO, or rotated through 180. Thus the
nozzle member can be positioned to eject air in one direction or
another, 180 apart, and provides for both rotational and braking
effort as required.
The central portion 86 of the housing on either side of
the central section is formed by spaced members 96 to provide an annular
air chamber 97. Small bores 98 extend through the inner members 96,
and air passes through the bores 98 to form an air bearing between the
periphery of the central portion of the rotor and the inner surfaces
of inner members 96.
Similarly end members lO0 and lOl form annular air
chambers 102 and 103, with small bores 104 extending through the inner
walls 105 of the chambers 102 and 103. Air flowing through the
bores 104 forms air bearings between the end surfaces 120 of the
central portion 83 of the rotor 80 and the end members 100 and 101.
Air under pressure, is fed to chambers 102 and 103 via
inlets 107 and 108 respectively and to chambers 97 via one or more
inlets lO9. Air escaping by flowing down between the end of the central
portion 83 of the rotor and inner wall 105 of end member lO0, at the
left side of Figure 8, can flow between the circumference of the reduced
diameter portion 84 and the end member into chamber llO and exhaust via
outlet lll.
Depending upon the size of cable, and the number of units
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~08~437
the cable needs to be divided into, so the rotor can have differing
numbers of holes 81. For example rotors wîth 2 to 12 holes can be
provided. Conveniently the dimensions of the rotor are standard,
apart from the number, and possibly diameter, of the holes 81.
Rotors can be replaced by removing the end portions 88 of the housing
82. The rotor 80 can then be slid out and another replaced. The
end portion 88 is located and heldin place by dowels 112 and cam
action studs 113.
In the example illustrated in Figures 8, 9 and 10, the
cable moves throughthe rotor in a direction indicated by the arrow
X in Figure 8. The device is mounted on the end wall of the inlet
end of the fluidized bed housing, the wall indicated at 114 in Figure
8. Thus Fîgure 8 is in the opposite sense to the arrangement
illustrated in Figure 6. While the twist of the cable units them-
selves will tend to rotate the rotor as the cable passes through the
fluidized bed, with large cables the size of the rotor can be such
as to create significant rotational drag. The use of the "turbine"
effect of the nozzle members 92 and grooves 93 can be used to overcome
this rotational drag. However, under some circumstances, the rotor
can tend to rotate faster than is desired due to the rotation
imposed on the motor by the cable. In such circumstances, by rever-
sing the inlet members, as described above, a braking effort can be
applied to the rotor. The "turbine" effect can be controlled by
controlling the air supply to the nozzle units 89. The number of
nozzle units used can be varied, and the number provided can also
vary. The end loading imposed on the rotor, or opening member, 80
by passage of the cable is supported by the end member 100 which
corresponds to the support member 25 in Figures 2 and 3 and support
member 40 in Figure 6. In the example illustrated in Figure 8 the
rotor or opening member 80 projects into a hole in the end wall 114.
However, the arrangement of Figures 8, 9 and 10 can be mounted on a
plate which in turn mounts on the end wall of the fluidized bed.
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