FI71628B - SAETTING OVER ANGLE PULVERFYLLNING AV EN KABEL - Google Patents

Description

ΓΒΐ m) NOTICE OF PUBLICATION, Sun 71628 BJ 11 UTLÄGG Nl N GSSKRIFT 1 · § £ § c <«) 01 1007 (51) Kv.lk.7lnt.ci. * H 01 B 13/16 (21) Patent application - Patentansökning 791920 ( 22) Date of application- -Ansökningsdag 15 · 06.79 (FI) (23) Starting date - Giltighetsdag 15-06.79 (41) Has become public - Blivit offentlig 29-12-79

National Board of Patents and Registration Date of display and publication - 10.10.86

Patent and registration authorities '' Ansökan utlagd och utl.skriften publiccrad (86) Kv. application - Int. trap (32) (33) (31) Privilege claimed — Begärd priority 28.06.78 Canada (CA) 306 ^ 02 Proven-Styrkt (71) Northern Telecom Limited, 1600 Dorchester Boulevard West, Montreal, Quebec, Canada (CA) (72) ) John Nicholas Garner, Pointe Claire, Quebec,

Arthur Stanley Hayes, Kingston, Ontario, Canada (CA) (7 * 0 Berggren Oy Ab (5 ^) Method and apparatus for filling a cable with powder - Sätt och anordning för pu1verfyI1 Ning av en kabel

The present invention relates to a method for filling a cable core comprising several conductors with powder. The invention also relates to a device for filling a multi-conductor cable with powder, the device comprising a housing with a bottom and inlet and outlet ends, the bottom of the housing having a porous element and means for supplying air through the porous element to fluidize the powder in the housing and surround the cable core with fluidized powder .

Powder-filled cables are known, in which case the powder is placed in the cable in an open state, i.e. the individual conductors are separated from each other, so that the powder can be introduced, e.g. by blowing or otherwise by forcing. There are various problems associated with known cable filling methods · One problem is the difficulty in achieving uniform filling. For example, in 2 71628 multilayer cables, it is very important that the filling is even because variations from one layer to another cause variations in the electrical characteristics of the different layers. In the case of telecommunication cables, this is in any case very undesirable and in most cases this is not acceptable at all.

The object of the invention is to provide a method and a device which do not have said disadvantages. The method according to the invention is characterized in that the conductors of the core are brought into a tightly closed state, that the conductors in this tightly closed state are passed through a fluidized bed containing filler powder, the filler powder passing between the conductors to fill the interstitial spaces of the core, followed by conductors in a tightly closed state. path they are routed outside the fluidized bed and that a sheath tape is immediately wrapped around the powder-filled core of conductors.

The device according to the invention is characterized by at least one inlet inlet of the housing; an input point for receiving a cable core comprising a plurality of conductors, the input point being dimensioned so as to hold the conductors of the core substantially tightly together; an outlet at the outlet end of the housing for removing the core with its conductors in a tightly closed state; and wrapping members adjacent the discharge head for wrapping the strip around the heart immediately after the repeated discharge end, the wrapping members and the associated discharge end being so limited that; the fluidized bed forms a rectilinear path through the exit point as well as the wrapping members.

Preferred embodiments of the invention appear from the claims.

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The invention will now be described in connection with a description of a method and the apparatus used therein with reference to the accompanying schematic drawings.

Figure 1 is a side view of an embodiment of the device.

Figure 2 schematically shows the cable entry and passage through the device.

Figure 3 is a perspective view of an embodiment of a device used to fill two cables.

As shown in Figure 1, the apparatus includes a main box or housing 10 with a top 11, an air tank 12 at the bottom, an air inlet 13, a dust outlet 14 and a powder inlet 15. The inlet end of the housing 10 has an inlet nozzle 16 and the other end has an outlet nozzle 17. Air tank 12 is separated from the main part of the housing 10 by a porous plate 18.

When the device is used, the housing 10 is filled with powder through the inlet 15 and compressed air is supplied to the air tank through the air inlet 13. Air passes through the porous plate 18 and fluidizes the powder in the housing 10, as shown in 19. A certain amount of dust is obtained and this leaves through the outlet 14.

Before filling the housing with powder, the cable conductors are fed in through the inlet and outlet nozzles 16 and 17. As shown in Figure 1, the cable conductors 20 pass through the preforming guide 21, after which they are formed into a cable as they pass through the inlet nozzle 16. The first length of molded conductors is fed through the housing 10 and out through the outlet nozzle 17. The molded conductors can then be attached to a suitable member for connection to a pull and receive mechanism.

As soon as the conductors have passed through the housing, the housing can be closed, the powder fed in and the supply of fluidized air switched on. The wires are then routed through the housing. As the conductors exit the housing through the nozzle 17, they are wrapped in the core sheath tape 25 by means of a mold 26. In the example shown, the mold 26 includes a tapered or conical inlet portion 27 and a parallel portion 28. The mold only shapes or wraps the sheath strip 25 around the conductors 20 to prevent loss of filler.

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The conductor gaps 20 may be separate, individual conductors or may comprise twisted pairs of conductors in telecommunication cables. The conductors are fed to the housing 10 through the inlet nozzle 16 in a substantially closed state. There may be certain smaller gaps between the conductors, for example as a result of a small opening of the conductors as they leave the inlet nozzle 16, but such an opening is always very small. The mutual distance between the conductors can be varied, for example, by changing the hole 16 of the nozzle inlet nozzle to change the filling amount. Although the conductors are in a substantially closed state and are usually arranged in several layers, surprisingly, even and complete filling of cables with a relatively large number of conductors is also obtained. For example, a satisfactory filling of a cable unit containing 50 pairs of conductors is obtained. The passage of the conductors through the housing 10 is illustrated in Figure 2.

Figure 3 shows a typical device for filling two cable cores, in this case each comprising 25 pairs of conductors. The two housings 10 are located side by side and are provided with a common powder supply line 40. In the example shown, rotating, vibrating plates 41 are arranged in the inlet nozzles to vibrate or oscillate the conductors as they pass through the housings. The powder feed is adjusted so that the thickness of the layer remains substantially unchanged. In an alternative arrangement, not shown, multiple cable cores may pass through a common layer.

The device is relatively inexpensive, simple and very efficient. The method results in evenly filled cable cores, so that the filling can be controlled and varied as needed. The cable then has uniform electrical characteristics.

Il

Claims (8)

A method of powder filling a cable core comprising a plurality of conductors, characterized in that the conductors (20) in the core are brought into a closely adjacent position, that the conductors in this tightly closed position are conveyed through a fluidized bed (19) which contains filling powder, wherein the filling powder penetrates between the conductors for filling the internal gaps in the core, that when the conductors present in a tightly closed position follow a rectilinear path these are conducted outside the fluidized bed, and that around the conductors formed, with The powder-filled core is immediately wrapped in a jacket band. 71628 2. A method according to claim 1, characterized in that powder is supplied to the fluidized bed (19) at a rate which maintains a substantially constant bed thickness. Method according to claim 1 or 2, characterized in that the conductors (20) are oscillated as they pass through the housing (10) containing the powder bed. 4. Device for powder filling a cable core, which comprises a housing (10) with a bottom and inlet and outlet ends, wherein at the bottom of the housing (10) there is a porous element (18) and means (13) for supplying air through the porous element (18) for fluidizing the powder in the housing (10) and for arranging the cable core with fluidized powder, characterized by at least one inlet (16) at the inlet end of the housing (10) for receiving a cable core having a plurality of conductors (20), each inlet (16) having such a dimension that it pours the conductors (20) in the core substantially tightly together; an outlet (17) at the outlet end of the housing (10) for removing the core while the conductors are in tightly closed condition; and adjacent to the outlet end wrapping means (26, 27, 28) for winding a band around the core immediately as it protrudes from the outlet end, the wrapping means (26, 27, 28) and the corresponding outlet end being such that the fluidized bed is formed in a rectilinear manner. through the outlet and the wrapping means. Device according to claim 4, characterized by an air box (12) mounted at the bottom of the housing (10), the means for supplying air comprising means for supplying air to said air box, and that the porous element (18) extends between the air box (12) and housing (10). Apparatus according to claim 4 or 5, characterized in that the housing (10) is provided with an upper portion (11) and that a dust release means (14) is connected to said portion.