GB2160499A - Drum - Google Patents

Abstract

A drum for winding for example electric cable, comprises a core (11) and end pieces (12) supported by the core. Each end of the core is provided with a section which is radially expandable. An end plug (13) is insertable into the core end and presses the said section against the edge (16) of an opening in the end piece. The core is made from metal plate and is provided with an inward facing bead (17) which determines the axial insertion depth of the plug, and an axial internal stop (18) formed as an outward facing bead on the core bearing against the inside of either end piece. The core may consist of a plurality of parts formed as curved plates (Figure 6, not shown) or flat plates (Figure 8, not shown). <IMAGE>

Description

SPECIFICATION Drum This invention relates to drums for winding up long objects, for example electric cable, iron wire, rope, etc.

The invention is based on the problem of accomplishing an optimized design regarding cost and handling aspects. Furthermore the design shall be such that on demand it is dismountable and thereby is of little bulk in order to be returnable to for example a cable manufacturer.

A large variety of drums, especially cable drums, are previously known. Designs consisting completely or partly of metal are known. Normally the mounting of end pieces to the known drums is done by inserting tongues on the core ends into cut-outs in the end pieces and then bending them over.

Repeated bending causes severe fatigue in the tongues, which will gradually break. Furthermore the mounting requires predetermined reciprocal positioning of end piece and core. Usually the manufacture of the end pieces requires a punching operation which is costly. Furthermore the stability is many times doubtful, especially if one or some of the tongues have been broken off.

This invention, with the purpose of setting these shortcomings aside, provides a drum for winding up long objects, for example electric cable, consisting of a core and end pieces supported by the core. The drum is distinguished by the core, which, at least at either end thereof, across the longitudinal direction of the core presents an expandable section, and that an end plug insertible into the area of said section presses said section against the edge of an opening in the end piece.

In a preferred version the core and/or the end plug exhibit a limiting stop which determines the axial insertion depth of the plug.

In order to simplify the positioning of the end piece, preferably an axial internal stop bears against the inside of each end piece.

In order to further support the positioning and improve the retaining of the end pieces, the core has at either end thereof at least one flange for bearing against the outside of the end pieces.

In one version which is suitable for manufacture, especially regarding plate, the end plug positioning stop is designed as a, relative to the core, inward facing and the axial internal stop is designed as an outward facing bead.

Suitably the core has the shape of a slitted hollow cylinder, on which at either end, an essentially circular end plug, along the whole periphery thereof, presses the said section of the core end against the edge of a circular opening in the end piece.

Friction increasing means, for example toothing, is suitably arranged at the end sections of the core to grip each end plug for the purpose of improving the engagement between the end plugs and the core.

In an alternative version the core is designed as a hollow cylinder which is slitted at both ends thereof.

In another alternative version the core consists of a number of, preferably part circular, part sections.

As mentioned the core is suitably manufactured from metal plate and the end plugs and end pieces are preferably manufactured from wooden chips and binder moulded into bodies provided with holes.

Some versions of the invention shall now be described with references to the drawings, where Figure 1 shows a first variant in a partly sectioned perspective view, Figure 2 is a top view of the drum in Figure 1, Figure 3 shows a second variant in a partly sectioned perspective view, Figure 4 is a top view of the drum in Figure 3, Figure is a partly sectioned perspective view of yet another version of the drum, Figure 6 is a top view of the drum in Figure 5, Figure 7 is a partly sectioned perspective view of yet another version of the drum, Figure 8 is a top view of the drum in Figure 7, Figure 9 shows a further modification within the scope of the invention, and Figure 10 is a top view of the drum in Figure 9.

The drum 10 in Figure 1 consists of a core 11 and end pieces 12 as well as end plugs 13 which hold the core and the end pieces together. The core is preferably manufactured from a relatively thin metal plate with a thickness in the range of a few mm, and it can for instance have the cylindrical shape shown in Figure 1 with a slit 14 extending from end to end.

The slit implies that the core becomes expandable and compressible across the longitudinal direction 15.

The end pieces 12 are preferably made from some material based on wood, for example wooden chips, which in a suitable way has been pressed to the required hardness and density. Also the end plugs 13 are made from a material based on wood and preferably consist of wooden chips, so called moulding chips, in other words wooden chips impregnated with carbamide, which have been moulded into the intended configuration.

In each end piece there is an opening 16, in Figure 1 of circular shape and with a dimension adapted to a width of the slit 14 in the order of a few mm when the core 11 is positioned in the openings 16 as shown in Figure 1.

This positioning of the end pieces and assembly of the core and the end pieces is accomplished with the end plugs 13. Each plug is insertable into the end of the core to an axial depth determined by a radially inward facing, encircling bead 17. This bead is suitably made in a roller curving machine at the same time as the core is bent to its desired shape.

Another bead 18 is accomplished in a corresponding way, although facing radially outwards. This bead 18 forms an internal support for the end piece 16.

The core in Figure 1 is at its outer ends provided with flanges 19 which form an outside support and guidance for the respective end piece.

Each end plug is dimensioned to press the core end against the edge 16 of the openings in the end pieces, so that the plug 13 and the end piece 12 through the friction engagement in practice become fixed against turning. Such a joint is necessary for winding up a cable, as the core is being rotated through engagement of a finger in a hole 20 in at least one of the plugs. The other hole 21 is used to take up the axle spindle of the winding machine and can furthermore, as well as the hole 20, be used in connection with dismounting of the drum. The mounting of the core and the end pieces accomplished through the tight fit can be dismantled by inserting a tube our a similar object through either of the holes and knock it against the inside of the plug at the other core end.

In the version shown in Figure 3 the expansion and contraction possibilities are accomplished through slitted tongues 22 at the core ends. in this case the core 14 is a cylindrical shell plate, which in other respects principally has the same end piece positioning and fixing arrangements as in Figure 1. Thus for example there are external flange elements 19 and contact beads 17 and 18.

In Figure 5 the core 11 consists of three part circular sections accomplished by three slits 14.

Friction increasing toothing 23 is shaped at the end of each respective section, which is shown by the circled detail in the Figure.

Figure 7 shows a version of the core and end plugs without rotary symmetry, in this case the core 11 and the end plugs 13 are mountable to a regular hexagonal cross section. The end pieces 12 are suitably designed with slits or similar which preliminarily hold the core sections fixed before the plugs are knocked in.

In Figure 9 a core 11 is shown consisting of three part circular sections, which are held in place in the end pieces 12 bythe end plugs 13 provided with an outer collar 24 for fitting against the outside of the end pieces. The outer flanges of the core ends can be left out, as is shown in the Figure, but they can also be included.

Claims (14)

1. A drum comprising a core formed of a metal plate, and a pair of end pieces supported by the core, wherein the core is provided at at least one end thereof with a section which is expandable across the longitudinal direction of the core, and which is adapted to bear on an opening in a corresponding end piece, and an end plug insertable into the expandable section and adapted to press said section against the edge of the said opening in the end piece.

2. A drum as claimed in claim 1, wherein the core includes an inwardly facing bead adapted to form a stop to limit the axial insertion depth of the plug.

3. A drum as claimed in Claim 1 or Claim 2, wherein the core comprises an outwardly facing bead adapted to bear against the inside of a corresponding end piece, and therebyto form an axial stop.

4. A drum as claimed in any one of the preceding claims, in which the core has at least one flange at the said at least one end thereof for bearing against the outside of the end piece.

5. A drum as claimed in any one of the preceding claims, in which the core has the shape of a hollow cylinder having a longitudinal slit, and wherein the said end plug is essentially circular and adapted to press the said section of the core end against the edge of a circular opening in the end piece along the whole periphery thereof.

6. A drum as claimed in any one or any of the preceding claims, wherein the said end of the core includes means for increasing friction between the end section of the core and the end plug.

7. A drum as claimed in any one of the preceding claims, wherein the core is a hollow cylinder and is provided with a plurality of slits at the said end thereof.

8. A drum as claimed in any one of Claims 1 to 3, wherein the core consists of a plurality of part sections.

9. A drum as claimed in Claim 8, wherein the said part sections are curved plates.

10. A drum as claimed in any one ofthe preceding claims, wherein the end plugs and the end piece are made from bodies containing holes, said bodies being moulded from wooden chips and binder.

11. A drum as claimed in any one of the preceding claims, wherein the said expandable section is provided, at both ends of the core.

12. A drum substantially as hereinbefore described with reference to and as illustrated by Figures 1 and 2, 3 and 4, 5 and 6, 7 and 8, or 9 and 10 of the accompanying drawings.

13. A kit of parts, comprising a pair of end plates, a pair of end plugs, and at least one core member, adapted to be formed into a drum as claimed in any one of the preceding claims.

14. Adrumforwinding up long objects, for example electric cable, comprising a core (11) and end pieces (12) supported by the core, and the core at at least either end thereof is provided with an expandable section across the longitudinal direction ofthe core in which an end plug (13) insertable into the region of said section presses said section against the edge (16) of an opening in the end piece, the core is made from metal plate and is provided with a stop (17; 24) formed as a relative the core inward facing bead which determines the axial insertion depth of the plug, and there is an axial internal stop (18) formed as an outward facing bead on the core bearing against the inside of either end piece.