CA1081437A

CA1081437A - Apparatus for use in fluidized powder filling of multiple core unit cables

Info

Publication number: CA1081437A
Application number: CA308,439A
Authority: CA
Inventors: John N. Garner
Original assignee: Northern Telecom Ltd
Current assignee: Nortel Networks Ltd
Priority date: 1978-07-31
Filing date: 1978-07-31
Publication date: 1980-07-15
Also published as: FI69721C; ES482908A1; AU4884179A; JPS5521894A; FI69721B; IT1122632B; NO151873B; DK321579A; FI792381A; NO792505L; EP0007634A1; EP0007634B1; BR7904713A; MX149857A; IT7924487A0; DE2963536D1; NO151873C

Abstract

APPARATUS FOR USE IN FLUIDIZED POWDER
FILLING OF MULTIPLE CORE UNIT CABLES
Abstract of the Disclosure For powder filling of cables, in a fluidized powder bed, it has been proposed to pass the cable core through the bed in a substantially closed condition. There is a limit to the number of conductors a core can have for effective filling. In the present invention the cable core is opened up into a number of core units by passing through an opening member. The opening member is freely ridable on the cable core and has a hole for each unit. The opener is held against a support member and an air bearing formed between the two members. Air is also usually fed to the holes in the opener member through which the core units pass to prevent flow of powder out from the bed. The opening member can be positioned in the fluidized bed or outside immediately prior to passage of the cable core through the bed. The units are each in a substantially closed condition in the bed and the units close to a single core also in the bed.

- i -

Description

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-- 1 - ~, .
q~ .

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 ;, -- 108143`7 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 .

.

~, .

r~ V81~37 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 ' :

,. .. . .
..

-~ 1081437 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.

-^` 1081437 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 -~` 108143`7 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.

-: -- 7 --~08143`7 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 A ~ :

. . .
.

~ OB1~37 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 . . . .

~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.

A

Claims

THE EMBODIMENTS OF THE INVENTION IN WHICH AN
EXCLUSIVE PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:-

1. Apparatus for use in fluidized powder filling of multiple core unit cable cores comprising an opening device for opening cable cores into a plurality of core units, the opening device comprising:
a support member;
an opening member positioned against said support member and including a plurality of holes extending in an axial direction therethrough, each hole adapted for passage of a core unit therethrough;
and means for supplying pressurized air between said opening member and said support member to form at least one air bearing therebetween;
the opening member freely rotatable upon the support member.

2. Apparatus as claimed in claim 1, said support member and said opening member mounted in a fluidized powder filling bed.

3. Apparatus as claimed in claim 1, said support member and said opening member mounted at an inlet end of a fluidized powder filling bed.

4. Apparatus as claimed in claim 1, including means for supplying pressurized air to said holes in said opening member at a position intermediate the ends of the holes.

5. Apparatus as claimed in claim 2, including an inlet die at an inlet end of said bed and an exit die at an exit end of said bed, said inlet die and said exit die each adapted to maintain said cable core in a closed condition.

6. Apparatus as claimed in claim 2 or 3, including means for wrapping said core after issuing from said bed.

7. Apparatus as claimed in claim 3, said bed having a wall at said inlet end, said opening device mounted on an outer side of the wall, the support member attached to said wall, and a hole extending through said inlet wall aligned with said opening member.

8. Apparatus as claimed in claim 7, said support member being a tubular member having a back surface positioned against said wall and an annular wall extending in a direction away from said inlet wall and defining a chamber within which said opening member is positioned.

9. Apparatus as claimed in claim 8, said chamber having a conical support surface at an inner end, said opening member including a forward, conical, surface in cooperative opposition to said conical support surface.

10. Apparatus as claimed in claim 9, including an annular channel formed in said back surface, means for feeding pressurized air to said annular channel, and orifices extending from said annular channel to said conical support surface for supplying the pressurized air between the support member and said opening member.

11. Apparatus as claimed in claim 8, said opening member including a cylindrical portion freely rotatable within said annular wall, an annular chamber extending around the outer periphery of the cylindrical portion, means for feeding pressurized air through said annular wall to said annular chamber, and bores extending from said annular chamber to said holes extending through said opening member for supplying said pressurized air to said holes.

12. Apparatus as claimed in claim 8, including an annular retaining member attached to an outer end of said annular wall and extending radially inward thereof, a front surface on said retaining member; a rearward bearing surface on said opening member in opposition to said front surface, an annular cavity in said retaining member; means for feeding pressurized air to said annular cavity and orifices extending from said cavity to said front surface to feed pressurized air between said front surface and said rearward bearing surface for formation of an air bearing therebetween.

13. Apparatus as claimed in claim 7, including a collector member mounted on an inner side of the wall at said inlet end, said collector member comprising an annular conduit, for collection of air flowing from between said support member and said opening member, and an outlet connected to said annular conduit.

14. Apparatus as claimed in claim 13, said outlet connected to an air space above said fluidized bed, said air space at a pressure slightly below atmosphere.

15. Apparatus as claimed in claim 1, said opening member including a central hole on the central axis of the opening member, and at least one circle of holes around said central hole.

16. Apparatus as claimed in claim 15, each of said holes in said at least one circle of holes being inclined inwardly towards said central axis from an inlet surface to an outlet surface on said opening member.

17. Apparatus as claimed in claim 15, said central hole being larger than any hole on said at least one circle of holes.

18. A method of fluidized powder filling a multiple core unit cable core, comprising opening said cable core to space apart said multiple core units, each containing a multiplicity of conductors, feeding said core units, each with its conductors closed together, through a fluidized powder bed, and closing said core units into a cable core in said fluidized powder bed.

19. A method as claimed in claim 18, including opening the cable core by passing the core units through holes in an opening member freely ridable on the cable.

20. A method as claimed in claim 19, including feeding pressurized air to said holes in said opening member to prevent escape of powder from said bed through said holes.

CLAIMS SUPPORTED BY THE SUPPLEMENTARY DISCLOSURE

21. Apparatus as claimed in claim 7, said support member mounted on said outer side of said wall and comprising a tubular housing having a cylindrical central portion and cylindrical end portions on either side of said central portion, said end portions having an internal diameter smaller than the internal diameter of said central portion, one of said end portions forming an end surface, said opening member comprising a rotor rotatably mounted in said housing and having a centre portion and end portions on either side of the centre portion, the diameters of the end portions and centre portion of said rotor being a close rotating fit in said end portions and central portion respectively of said housing;
axially extending grooves in the periphery of the central portion of the rotor and at least one nozzle member in the central portion of said housing, and air supply means to said nozzle member, whereby pressurized air ejecting from said nozzle member acts on said grooves to provide a rotational force on the otherwise freely rotatable rotor;
said end portions of said housing including surfaces in opposition to end walls on said central portion of said rotor, and means for supplying pressurized air between said end walls and said surfaces, and means for supplying pressurized air between the periphery of the central portion of the rotor and the inner surface of the central portion of the housing to form at least one air bearing therebetween.

22. Apparatus as claimed in claim 21, said axially extending grooves being of hemispherical cross-section, said nozzle member having an outlet inclined relative to the axes of the grooves.

23. Apparatus as claimed in claim 21, each said nozzle member mounted in a nozzle unit, and including means for attaching said nozzle unit to said housing, said means for attaching said nozzle unit arranged to permit attachment of said nozzle unit in either of two positions, of 180° rotation apart.

24. Apparatus as claimed in claim 21, said opening member including a plurality of circles of holes around said central hole, the axes of all of said holes parallel to each other.

25. A method as claimed in claim 19, including feeding pressurized air between the opening member and a support member on said fluidized bed for formation of at least one air bearing between the support member and the opening member.

26. A method as claimed in claim 19, including ejecting pressurized air from a housing surrounding said opening member, the air impinging on formations on the periphery of the opening member to produce a rotational force on the opening member.

27. A method as claimed in claim 26, said rotational force in a direction to rotate the opening member in the same direction as rotation resulting from the passage of the cable core units.

28. A method as claimed in claim 26, said rotational force in a direction to oppose the rotation of the opening member resulting from the rotational form resulting from the passage of the cable core units.

29. A method as claimed in claim 18, including wrapping a tape round the closed cable core after exiting from the fluidized powder bed.