EP0935579B1

EP0935579B1 - Spool made of plastics

Info

Publication number: EP0935579B1
Application number: EP97912604A
Authority: EP
Inventors: Inga-Lill HÖGLIND; Ingvar Svensson
Original assignee: Hoglind Inga-Lill; Svensson Ingvar
Current assignee: HOEGLIND, INGA-LILL; SVENSSON, INGVAR
Priority date: 1996-11-04
Filing date: 1997-11-04
Publication date: 2003-05-21
Anticipated expiration: 2017-11-04
Also published as: NO313379B1; AU4972997A; SE507320C2; NO992133D0; SE9604038D0; DE69722232T2; EP0935579A1; WO1998019953A1; NO992133L; SE9604038L; DE69722232D1

Description

The present invention relates to a spool of a plastics material for reception thereon of a strand-like material, such as e.g. tape, cable, wire and the like, comprising two preferably disc-like end members held together in spaced-apart relationship by a tubular core extending between said end discs. The end discs and the core are formed with portions of complementary configuration, which are fitted into one another upon assembly of the spool. The end discs are provided with protruding supports having radial, grip lugs thereon. The protruding supports project axially from the facing sides of the discs, and in the area of its ends the core is provided with grip portions comprising grip edges.

Spools of this kind usually are manufactured by moulding the end discs separately and then gluing them to the core. In order to satisfy various requirements concerning the volume and the diameter and length dimensions, it is necessary to manufacture spools of a large number of different dimensions. It should be appreciated that numerous different end-disc diameter sizes could be used together with a core of a specific length just like numerous different core lengths could be used together with an end disc of a specific diameter size. When glue is used as the bonding agent to fasten the end discs to the core it is very difficult to find a glue that is suitable from an environmental point of view. In addition, factory-finished spools are very bulky to store as well as to transport and handle.

Another way of manufacturing a spool is to assemble the spool from two parts of end-disc members and one middle tubular part. Such a spool is disclosed in DE 22 59 364, upon which the preamble of the first claim of the present application is based. A spool of that kind is having cantilever-like grip lugs at the end-discs, intended to engage in recesses in the middle tubular part for assemblage.

The main object of the invention is to provide a spool obviating the necessity of using environmentally harmful bonding agents while at the same time the number of pieces necessary to supply the desired spool volumes and spool dimensions is considerably reduced. A further object of the invention is to provide a reliably operating spool structure that requires but a minimum storage and transportation space.

This object is achieved by means of a spool according to claim 1 wherein said end discs are provided with protruding supports having radial, grip lugs thereon, said protruding supports projecting axially from the facing sides of said discs, and in the area of its ends said core is provided with grip portions comprising grip edges said grip lugs being non-resilient by having stiffening webs extending radially from said grip lugs towards said end disc centre, i.e. rigid grip lugs, and in that said grip edges are arranged, in the interfitted position of the core and the end discs, to be engaged by the end-disc grip lugs after the latter, upon interfitting of the end discs and the core, having been forced past the core grip portions while making use of the resilience of the plastic material by extending the core in the circumferential direction. Owing to this arrangement a strong spool is obtained, wherein the user need only purchase and keep in stock a minimum number of parts that he may adapt to his spool-volume needs. For instance, the buyer could purchase end discs of only one or in any case a very reduced number of diameter sizes, and with the aid of cores of different lengths he is able to make the adaptations necessary for the desired volume in view of the material to be wound onto the spool. It is, of course, likewise possible to purchase cores of one or at least only a few different dimensions and adapt the volume with the aid of end discs of different diameter sizes. Because the end discs are press fit onto, and not integrated with the core, the assembly of the parts may be effected by the user, which offers considerable advantages from a transportation point of view. It should be appreciated that just like before there is nothing to prevent assembly of the spool at the place of moulding of the plastic components. This arrangement also gives a very strong construction with minimum risks for the components separating when handled roughly.

Preferably, the grip lugs of the end discs are configured as hook-like tongues comprising a wedge-shaped face turned away from the associated end disc and a grip edge facing the associated end disc for snap engagement with the grip portion in the core. Accordingly, the assembly may be performed conveniently by merely pressing the end discs and the core together axially.

Preferably also, the grip tongues are directed radially outwards, and the grip edges formed in the core are recesses made in the core wall, preferably in the shape of apertures extending through the core wall. In addition, the grip lugs on the end discs preferably are spaced apart along a circular arc, second protruding supports preferably being arranged between the first protruding supports, said second supports having wedge-shaped sloping ramps to be ridden on by the core. Furthermore, since the grip lugs on the end discs are non-resilient, i.e. stiff, whereby passage of said lugs by means of the grip portions of the core is allowable by extension of the core in the circumferential direction thereof, a very reliable, durable joint is achieved once the components have been pressed together, a joint which an unauthorised person may disconnect only with considerable difficulty. The arrangement prevents the joint from being disconnected and the components again be fitted together in a manner jeopardising the strength of the spool.

One embodiment of the invention will be described in closer detail in the following with reference to the accompanying drawings, wherein

Fig. 1 is a perspective view of a spool designed in accordance with the invention,

Fig. 2 is an exploded view of one end portion of the core and the inner face of an end disc of the spool in accordance with the invention, shown in an exploded view in a non-mounted condition,

Fig. 3 is an axial cross-sectional view through the central part of the end disc and the end portion of the core intended for the same spool as in the preceding drawing figures, and

Figs 4-6 are fragmentary axial views as seen from the inner face of one end disc and showing the sequential deformation of the core as it is being fitted onto the end disc.

The spool illustrated in the drawing figures consists of two end discs 1 which are held together in spaced apart relationship by a tubular core 2. The end discs 1 preferably are identical but could equally well differ in shape as well as in configuration, should this be desired. In accordance with the shown embodiment the outwardly directed face of the end discs are formed with a number of stiffening ribs 3, 4 and 5. It is of course equally possible to provide the end discs with stiffening ribs on their inner face or to design them with a smooth outer face or both faces smooth, or to form them with stiffening ribs having a different appearance and extension. The spool may be used to receive any windable material, such as tape, cable, wire and the like. Numeral reference 6 designates protruding supports generally, said supports projecting from the inner face of the end disc and in accordance with the shown embodiment they consist of an annular, axially protruding flange 7 and of grip lugs 8 distributed along the flange periphery and projecting radially beyond the outer face of the flange. The grip lugs 8 form hook-shaped grip tongues comprising a wedge-shaped face 8a turned away from the inner face 9 of the end disc, and a grip edge 8b turned towards the inner face of the end disc. The grip tongues are stiffened by a stiffening web 10 extending radially towards the disc centre, the grip portions consequently being non-resilient (non-flexible). The upper half of Fig. 3 is a sectional view on the line indicated in Fig. 2 by arrow IIIa and the lower half is a sectional view indicated in Fig. 2 by arrow 111b. Numeral reference 11 designates a stiffening web which like stiffening web 10 extends radially and is formed with a wedge-like sloping edge face 12. As most clearly apparent from Fig. 3 the parts of the annular flange 7 extending between the grip tongues 8 have an obliquely bevelled face 13 on its edge turned away from the end disc. The oblique bevel 13 forms a continuation of the wedge-shaped edge face 12 of the stiffening web 11. Also the stiffening web 10 has a wedge-shaped face 14 which forms a continuation of the wedge-shaped face 8a of the engagement tongue 8. Numeral reference 15 designates a centre hole formed in the end disc by means of which the spool may be rotatably mounted on e.g. a shaft. Numeral reference 16 designates apertures formed adjacent the ends of the core 2, the aperture edges 18 closest to the core end 17 forming grip edges which cooperate with the grip edges 8b on the grip tongues. The spool is assembled by the core being pressed against the end disc 9. When the end edge 17 of the core comes into contact with and runs along the oblique faces 14 and 8a on the stiffening webs 10 and the grip tongues 8, respectively, the parts of the core that are positioned between the grip tongues will be distended as appears from Fig. 5. Upon continued pressing-together of the two components this movement of the tubular wall of the core is, however, opposed in a direction towards the centre by the between wedge faces 12 as well as by the wedge face 13 on the annular support means 6, whereby the core is forced to re-assume a circular configuration, as shown in Fig. 6. When the end portion of the core moves past the grip tongues and thus is forced outwards, onto the outer periphery of the annular flange 7, the material of the core is extended in the circumferential direction against the action of its resilience. When the grip tongues snap into the engagement apertures 16, the core again assumes its circular shape. Extension of the portion of the core closest to the end edge thereof, in which core portion the material possesses remaining resilience, will result in the core fitting narrowly around the external face of the annular support 7. By adequately adapting the distance A from the grip edge 8b on the grip tongue to the inner face of the end disc relative to the distance B from the grip edge 18 of the grip apertures to the end edge 17 of the central component a very stable and durable joint is obtained. Unauthorised breaking up of this joint is very difficult, since the grip tongues, owing to the stiffening means 10 at their rear, cannot be forced back through the grip apertures, and any attempts to prise loose the end portion of the core from the grip tongues with the aid of a tool of some kind will only result in damaging of the engagement parts. Should it have become possible to thus separate the components, unauthorised re-assembly thereof, which could endanger the function of the spool as it is used again, is at least prevented.

The invention is not limited to the embodiment described herein and illustrated in the accompanying drawings by way of example but could be varied as to its details within the scope of the appended claims without departure from the basic idea of the invention. For example, in accordance with the shown embodiment the grip tongues 8 are provided in a number of four as are also the projecting supports formed by the stiffening webs and positioned between the tongues. Within the scope of the invention, this number could, of course, be higher or lower. It is not either necessary that the number of projecting supports having grip tongues formed thereon is identical with the number of projecting supports positioned therebetween. As an alternative, the annular flange 6 need not be continuous along the entire periphery. Instead, it could be divided into a number of sections spaced somewhat apart. With a sufficiently large number of wedge-shaped edges 12 to be ridden by the core the flange-shaped annular member 7 could, however, be omitted altogether.

Claims

A spool made of plastics material for reception thereon of a windable material, such as e.g. tape, cable, wire and the like, comprising two preferably disc-like end members (1) held together in spaced-apart relationship by a tubular core (2) extending between said end discs, said end discs (1) and said core (2) are formed with portions of complementary configuration, said complementary portions being fitted into one another upon assembly of said spool, said end discs (1) being provided with protruding supports (6, 8) having radial, grip lugs (8) thereon, said protruding supports projecting axially from the facing sides of said discs, and in the area of its ends said core is provided with grip portions comprising grip edges (18), characterised in that said grip lugs (8) being non-resilient by having stiffening webs (10) extending radially from said grip lugs (8) towards said end disc (1) centre, i.e. rigid grip lugs, and in that said grip edges (18) are arranged, in the interfitted position of the core and the end discs, to be engaged by the end-disc grip lugs (8) after the latter, upon interfitting of the end discs and the core, having been forced past the core grip portions while making use of the resilience of the plastic material of the core (2) by extending the core in the circumferential direction.
A spool as claimed in claim 1, characterised in that the grip lugs (6, 8) of the end discs (1) are configured as hook-like tongues (8) comprising a wedge-shaped face (8a) turned away from the associated end disc and a grip edge (8b) turned towards the associated end disc for snap engagement with the grip portions in the core.
A spool as claimed in claim 2, characterised in that the grip tongues (8) are directed radially outwards.
A spool as claimed in any one of claims 1-3, characterised in that the grip edges (18) formed in the core (2) are formed by grip recesses (16) formed in the core wall.
A spool as claimed in claim 4, characterised in that the grip recesses (16) are apertures extending through the core wall.
A spool as claimed in any one of claims 1-5, characterised in that the grip lugs (8) on the end discs are spaced apart along a circular arc.
A spool as claimed in claim 6, characterised in that between the protruding supports (8) formed on the end discs second protruding supports (7, 11) are provided having wedge-shaped sloping ramps (13, 12) on which the core (2) rides.
A spool as claimed in claim 7, characterised in that said second protruding supports (7) extend arcuately between said first protruding supports so as to form an annular means jointly with said first supports, one side face of said annular means having a diameter size corresponding to or exceeding the diameter size of one side of the core.
A spool as claimed in claim 8, characterised in that said diameter sizes are adapted for press fit engagement between the protruding supports of the end discs and the core wall.