Plastic bobbin and a method of manufacturing such a bobbin

SWEDEN («j PATENT WRITING (13) C2 (H) 520 441

<img file="SE520441C2_D0001.tif" />

(19) SE ₍₅₁₎

International class ⁷

B65H 75/14, 75/50

PATENT AND REGISTRATION (45) (41) (22) (24) (62) (86) (86) (83)

Patent issued 2003-07

Application widely available 2003-07 The patent application was filed in 2002-01

Running day 2002-01

Tribal application number

International filing date Filing date for European patent application Deposit of microorganism (21)

<td colspan="2"> 08</td><td>number 0200251 7</td>

<td colspan="3"> 08</td>

<td> 30</td><td colspan="2">Application received as:</td>

<td colspan="3"> 30</td>

<td></td><td>X</td><td>Swedish patent application</td>

<td></td><td></td><td>completed international patent application</td>

<td></td><td></td><td>with number</td>

<td colspan="2"> □</td><td>converted European patent application with number</td>

(30) Priority information (73) (72) (74) (54) (56) (57)

PATENT HOLDER Sibil International AB, Kårevägen 21, Furuby

360 51 Hovmantorp SE

INVENTOR Sven-Ingvar Lundahl, Hovmantorp SE

OMBUD AWAPATENT AB

NAME Plastic bobbin with cylinder and all-round, one-piece end flanges, and ways of making such a

CALLED PUBLICATIONS:

SE B 469 836 (B65H 75/22), WO Al 9 104 218 (B65H 75/22), DE Al 19 601 966, GB A 1 303 063 (B65H 75/50),

US A 1,437,954 (206/55)

SUMMARY:. ",. . , tr. The plastic bobbin (1) has a cylinder (2) with circumferentially integral end flanges (3) formed from a U-shaped channel. Each flange (3) is constituted by a plurality of spaced apart substantially radial flange elements (4) distributed along the circumference of the cylinder (2).

In one way of manufacturing such a bobbin, a U-shaped channel is produced by injection molding. The U-shaped channel is shaped so that its sidewalls consist of a plurality of spaced apart wall elements which are distributed along the length of the channel. The channel is bent to form said cylinder (2) and its ends are connected in this bent position to each other.

<img file="SE520441C2_D0002.tif" />

The numbers in brackets indicate international identification code, INID code. Letters in clamps indicate international document code.

520 441

SUMMARY

A plastic bobbin (1) has a cylinder (2) with circumferentially integral end flanges (3) formed from a U-shaped channel. Each end flange (3) consists of a plurality of spaced apart substantially radial flange elements (4) distributed along the circumference of the cylinder (2).

In one way of manufacturing such a bobbin, a U-shaped channel is produced by injection molding. The U-shaped channel is shaped so that its sidewalls consist of a plurality of spaced apart wall elements which are distributed along the length of the channel. The channel is bent to form said cylinder (2) and its ends are connected in this bent position to each other.

Publication image: Fig. 4

520 441

Technical area

BACKGROUND OF THE INVENTION The present invention relates to a plastic bobbin having a circumferentially integral end flange cylinder formed of an un-shaped channel and a method of manufacturing such a bobbin in which a U-shaped channel is produced and bent for forming said cylinder with end flanges, wherein the ends of the channel in this curved position are connected to each other.

Technical background

Bobbins are used for winding of cable, among other things, and they can be manufactured in a variety of ways and materials. In smaller sizes, up to about 400 mm, they are usually made of plastic or paper. They can be made in one piece or several parts, which are then assembled.

From GB-1 303 063 it is known to produce a bobbin by bending a plastic channel so that its ends meet and a cylinder with circumferential end flanges is formed, after which the ends are welded or glued together. The plastic duct is made by extruding or hot forming a plastic strip and is provided with transverse creases to enable it to bend into a cylinder.

The disadvantages of this manufacturing method are that the process is time-consuming, since the production takes place in several steps and different machines or tools are required for each step, and that the formation of folds results in high material consumption.

Summary of the Invention

The object of the invention is to provide a method which makes it possible to simplify the production of a bobbin of the above-mentioned type and to reduce the material consumption thereof. The object of the invention is further to provide such a bobbin which can be made of lesser amount of material compared to the known bobbin in

520 441 of similar size and furthermore has the advantage that it can be transported and stored in a more rational way.

This object is achieved with respect to the bobbin with a bobbin which is of the type mentioned in the introduction and characterized in that each end flange consists of a plurality of spaced apart substantially radial flange elements distributed along the circumference of the cylinder.

In order for the end flanges of the bobbin to have sufficient strength, its flange elements over their entire radial extent are preferably substantially constant in circumferential direction, each end flange element having a total circumferential extent substantially equal to the circumference of the cylinder.

To facilitate bending, the bobbin preferably has a plurality of axial grooves formed in the outer casing surface of the cylinder, each groove extending over the entire length of the cylinder between a point between two adjacent flange elements in one end flange and a point between two adjacent flange elements in the cylinder. the other end flange.

Each flange member preferably has at its radially inner end a lug extending beyond the inner casing surface of the cylinder and having a radially inwardly decreasing extent in the circumferential direction. The U-shaped channel can be bent until each heel has come into contact with an adjacent heel. Thus, the lugs make it easier to mold the U-shaped channel into a cylinder which retains its cylinder shape and does not collapse during use. In an alternative embodiment, the inner casing surface of the cylinder has a plurality of axial grooves, each groove extending over the entire length of the cylinder between a point between two adjacent flange elements in one end flange and a point between two adjacent flange elements in the other end flange. The grooves in the inner casing surface of the cylinder are preferably located opposite the grooves in its outer casing surface and preferably have wedge-shaped cross-section.

520 441

Preferably, at least one flange member in one end flange has at its radially outer end an associated articulated extension which at its free end is hookable on the other end flange.

The above object is achieved in the manner of the U-shaped channel being produced by injection molding and given such that its sidewalls comprise a plurality of spaced apart wall elements which are distributed along the length of the channel.

The channel ends are preferably connected to each other by introducing projections formed on an extension of the bottom of the channel longitudinally projecting at one channel end into holes formed in the bottom of the channel at the other channel end.

To facilitate bending of the channel, its bottom is provided during injection molding, internal transverse grooves, which extend over the entire width of the bottom between a point between two adjacent wall elements in one channel wall and a point between two adjacent wall elements in the other channel wall.

Preferably, each wall element during the injection molding at its bottom connected to the bottom is provided with a protrusion extending beyond the bottom and having a longitudinal extension decreasing in the direction of the wall element, the duct bending until each protrusion has come into contact with an adjacent protrusion, whereby forms a stop, which causes the duct to form into a cylinder when bending. Alternatively, the bottom of the channel during injection molding may be provided with exterior transverse grooves extending over the entire width of the bottom between a point between two adjacent wall elements in one channel wall and a point between two adjacent wall elements in the other channel wall.

520 441

Brief description of the drawings

The invention will now be described in more detail with the aid of a preferred but not limiting embodiment and with reference to the accompanying drawings.

Fig. 1 is a side view showing a U-shaped channel used to produce a bobbin according to the invention.

Fig. 2 is a sectional view along line II-II of Fig. 1 showing a channel segment of the channel.

Fig. 3A shows the channel segment in section along the line

IIIA-IIIA in Fig. 2.

Fig. 3B shows the channel segment in section along the line IIIB-IIIB in Fig. 2.

Fig. 4 is an end view showing a bobbin made of a curved channel according to Figs. 1 and 2.

Fig. 5 is a sectional view along the line VV in Fig. 4 and shows the bobbin.

Description of preferred embodiments

The bobbin 1 according to the invention is made of plastic and has a cylinder 2 with a circumferential end flange 3 at each cylinder end. Each end flange 3 consists of a plurality of spaced apart radial flange elements 4 which are perpendicular to the cylinder axis and evenly distributed along the circumference of the cylinder 2. All of the flange elements 4 in the preferred embodiment have the same shape and size but they could also be of different shape and / or size. The flange elements 4 are essentially in the form of an elongated rectangle, each flange element being connected to the cylinder 2 at one short side of the rectangle. The total width of the flange elements 4 in each end flange 3 is approximately equal to the circumference of the cylinder 2. For increased strength, the flange elements 4 are internally provided with radial stiffeners 14 or have an arched cross-sectional shape.

Each flange element 4 in one end flange 3 is arranged opposite a flange element 4 in the other end flange

3rd Between the flange elements 4 in each pair of adjacent flange elements, the cylinder 2 has axial grooves 5 in its

520 441 outer mantle surface. These grooves 5 extend over the entire length of the cylinder 2.

In an alternative, not shown embodiment, the inner casing surface of the cylinder also has axial grooves between the flange elements 4 in each pair of adjacent flange elements, which grooves extend over the entire length of the cylinder 2 and have a wedge-shaped cross-sectional shape.

Each cylinder portion 2 'between two adjacent grooves 5 has an outwardly curved cross-sectional shape, as shown in Fig. 3B, or an inwardly curved cross-sectional shape. To provide a stiffer cylinder, these portions 2 'may be given a more pointed cross-sectional shape, as indicated by dashed lines in Fig. 3B.

Each flange member 4 has at its radially inner end a lug 6 which extends beyond the inner casing surface of the cylinder 2 and has a radially inwardly tapered extension in the circumferential direction (see Figs. 1 and 4). Each bell 6 tapers radially inwardly so that, as seen in the axial direction, it takes the form of a radially outer portion of a circle sector whose radius is equal to the inner radius of the cylinder 2 and whose tip angle is 360 ° / N, where N is equal to the number of flange elements in each end flange 3.

One or more flange elements 4 in one end flange are provided at their radially outer end with an associated conductor extension 7, the free end of which is to be hooked to a hook 19 on a flange element 4 in the other end flange so that the extension 7 forms a transport cover for a cable wound on the coil.

The outer casing surface of the cylinder 2 has a hook 8 in which a cable end can be hooked when winding a cable on the bobbin.

The bobbin 1 is manufactured in accordance with the invention in that a U-shaped channel 9 is injection molded of plastic and then bent together to form a cylinder 2 with an end flange 3 at each cylinder end. The bottom 10 of the U-shaped channel 9 forms the cylinder 2, and its walls 11 form the end flanges 3. In order to be able to bend the channel 9 together, its walls 11 are formed by a plurality of substantially rectangular wall elements 12 which are spaced apart and evenly spaced. along the length of the channel 9. As the channel 9 is bent, the wall elements 12 are removed from each other in the manner shown in Fig. 4.

The channel ends 13 are connected to each other by inserting projections 15, which here are in the form of hooks, which are formed on a longitudinal extension 17 of the channel 10 at one of the channel ends 13 of the channel 9, into holes 16 formed in the bottom of the channel. at the second channel end 13 (Fig. 2). Of course, it is also conceivable to design the holes in the extension 17 at one channel end 13 and the projections at the other channel end 13.

The bottom extension provided with the projections 15

17 at one channel end 13, there is also an opening 18 through which the hook 8, formed at the other channel end 13, is inserted when connecting the channel ends 13.

The bottom 10 of the channel 9 is provided with internal transverse grooves 5, which make the channel easier to bend.

In order to facilitate the formation of a cylinder 2, when bending the U-shaped channel 9, and to prevent the cylinder from collapsing, in the use of the bobbin 1, the wall element 12 is provided with a lug 6 extending beyond the bottom 10 and having a longitudinal decrease in the channel 9. extending in the direction from the wall element. The channel 9 can be bent until each bell 6 comes into contact with an adjacent bell 6. Alternatively, during the injection molding, the bottom of the channel 10 is provided with transverse grooves extending over the entire width of the bottom between a point between two adjacent wall elements 12 in one channel wall 11 and a point between two adjacent wall elements 12 in the other channel wall 11.

In addition to winding the cable, the bobbin according to the invention can also be used for winding, for example, ropes, ropes, hoses, narrow cloth and the like.

r λ η ozu