GB1602204A

GB1602204A - Method of making hollow bodies by winding

Info

Publication number: GB1602204A
Application number: GB6706/78A
Authority: GB
Original assignee: Individual
Current assignee: Individual
Priority date: 1977-02-27
Filing date: 1978-02-20
Publication date: 1981-11-11
Also published as: YU43278A; AT367350B; YU168482A; NL7802068A; IT1092919B; IT7820618A0; NO780632L; DD136255A5; ATA100778A; DE2808102A1; SE427338B; SE7802216L; CH614658A5; CS207588B2; FR2381621A1; JPS53106922A

Abstract

For producing elongated hollow bodies which are round in cross-section, numerous filaments (6) are clamped parallel to one another distributed round the internal circumference of the body (30) to be produced, so that a winding core results which is subsequently wound, so that it represents a lost core. During winding, the thus longitudinally clamped filaments of the winding core are, because of the winding tension, deflected inwards so that the hollow body takes on the form of a hyperboloid. By cutting through a hollow body of this kind in its centre, poles can be produced which serve, for example, for carrying electrical lines. These poles are distinguished by an especially high strength. <IMAGE>

Description

(54) METHOD OF MAKING HOLLOW BODIES BY WINDING (71) I, ROLAND FREHNER, a citizen of Switzerland, residing at Tolstrasse 17, 8620 Wetzikon, Switzerland, do hereby declare the invention for which I pray that a patent may be granted to me, and the method by which it is to be performed, to be particularly described in and by the following statement: This invention relates to a method of making hollow bodies by winding material in thread or strip form on to a core and to a winding machine for carrying out such a method.

The invention is based on the problem of providing a method of making hollow bodies by winding material in thread or strip form on to a core, which method makes it possible easily to produce bodies of various dimensions, without a core of another material having to be made in a separate process.

According to the present invention there is provided a method of making a hollow body by winding material in thread or strip form onto a core in which thread or strip lengths are secured in tension, and otherwise unsupported over their lengths, between two rotatable tensioning members to form the core, the two tensioning members being adjustably spaced apart by a distance corresponding to the axial length of the body to be produced and the core formed by the thread or strip lengths being incorporated into or forming part of the body being produced. The winding core so produced constitutes a "lost core" forming part of the body to be produced.

This method can be performed such that, after winding material over the core threads or strips, further threads or strips can be tensioned over the resulting partially formed body, parallel to the threads or strips of the core. This operation can be repeated a number of times, until the hollow body reaches the desired wall thickness. The threads or strips forming the core as well as any further threads or strips to be tensioned, hereinafter referred to as strand material, are secured to the two tensioning members in the region of the peripheries thereof, the distance between which members is set to correspond to the axial length of the body to be produced. The tensioning members are rotated for example each by a respective drive, and the winding material is fed thereto by a reciprocably movable feed means. The strand material and winding material used may be synthetic resin-impregnated glass fibre rovings so that, when the material hardens, there is a fixed bond. A suitable synthetic resin is for example polyester.

The invention also proposes a winding machine for carrying out the method, including two tensioning members which are mounted rotatably, coaxially and at an adjustable spacing from each other corresponding to the axiallength of the body to be produced, which are each connected to a rotary drive, and which each have means for securing threads or strips, to be tensioned, between the two tensioning members, a thread or strip feed means, and means for guiding and reciprocating the feed means on a path extending substantially parallel to the axis of rotation of the tensioning members.

The invention is described in greater detail hereinafter with reference to an embodiment shown, by way of example in the accompanying drawings, in which: Figure 1 is a front or plan diagrammatic view of a winding machine for carrying out the method of the invention, Figure 2 is a circuit diagram of a device for controlling the various drives of the winding machine of Figure 1, Figure 3 is a plan view, half in cross-section, of one of the tensioning members of the winding machine of Figure 1, with its mounting and its drive, and Figure 4 is a sectional view on an enlarged scale of a part of the tensioning member of Figure 3, having a means for securing one end of a thread or strip.

A winding machine for carrying out the method of the invention, as shown in Figure 1, has two tensioning members 2 and 4 for strand material 6, and a feed means 8 for winding material 10.

As shown in Figure 3, the two tensioning members 2 and 4 are each carried by a shaft 12 which is mounted in a radical bearing 14 and an axial bearing 16, in a cup-shaped housing 18.

The housing 18 has a shaft 20 which extends parallel to the shaft 12 or coaxially therewith, and which is mounted for axial displacement in a frame portion 22 or 24 respectively. Disposed at the end of the shaft 20 is a screw thread 26 so that a screw nut 28 which engages with the thread 26 can be used to tension the strand material when secured to the respective tensioning member. The two frame portions 22 and 24 are connected by a portion (not shown) of the machine frame, for carrying the tensioning forces. For the purposes of producing hollow bodies 30 of different lengths, the two frame portions 22 and 24 can be adjustable relative to each other by means (not shown), for example a spindle drive. The adjusting means or the spindle drive can also be used for precisely adjusting the tension in the strand material, for example in dependence on the winding operation, in order to produce a given hyperboloid form.

Secured on the shaft 12 is a gearwheel 32 with which engages the pinion 34 of an electric motor 36 or 38 respectively. The electric motor is flange-mounted on a housing place 40 which closes the cup-shaped housing 18 about the shaft 12. A sealing ring 42 is provided for sealing between the shaft 12 and the housing plate. A coil spring 44 disposed between the end wall 46 of the housing 18 and the end of the shaft 12 ensures that the balls of the axial bearing 16 cannot fall out of the bearing tracks, when the shaft 12 is moved when the member 2 is empty. The member 4 which is remote from the member 2 is mounted and driven in the same manner as shown in Figure 3, with the difference that the corresponding means are arranged in the reverse manner or in mirrorimage relationship.

The strand material 6, or the numerous glass fibre rovings 48 can be secured by clamping in the manner shown in Figures 3 and 4.

The roving is fitted through one of the bores 49 to 50 and a clamping ring 52 to 54 which is laid in a groove intersecting the respective bore is pressed onto the roving 48 by screws 56 to 58 respectively. The rovings are first secured in the radially inward bores 49, until they form in the peripheral direction an e.g. cylindrical body comprising numerous rovings lying parallel to each other. This first roving structure serves as a winding core. A further layer of rovings extending parallel to the axis is preferably tensioned between the members 2 and 4, only after the synthetic resin-impregnated rovings which form the winding material 10 have already been wound around the winding core in one or more layers, as shown in the cross-sectional view in Figure 3. Instead of securing the strand material by means of the clamping rings 52 to 54 and the screws 56 to 58, the strand material can also be secured by means of hooks (not shown) secured to tensioning members 3 and 4 respectively. For this purpose a roving is taken without interruption from one tensioning member 2 to the other tensioning member 4 and there passed over one of the hooks. Instead of hooks, the tensioning members may also be provided with groove-shaped recesses. In addition, each tensioning member may comprise a plurality of grooved rings which can be pushed one over the other, so that, after the smallest grooved ring has been fixed in place, the next larger ring is pushed from the outside over the smallest ring, the next larger ring previously having been held in a space between the gearwheel 32 and the smallest ring. Finally, the strand material may be secured to the tensioning members by means of clamping eccentric which are each connected to a respective clamping lever.

If the winding core is formed by taking a roving back and forth over fixing members on the tensioning members 2 and 4, the back and forth movement, or the feed of the roving, may be effected by the feed means 8. For this purpose, a guide arm (not shown) with moving rollers may be secured on the housing 60 of the feed means.

The feed means 8 or its housing 60 is guided on a rail 66 by means of wheels 62 and 64, and is reciprocated along the rail on a path extending substantially parallel to the axis of rotation of the members 2 and 4 by the drive of an electric motor 68 which is drivingly connected to the wheel 62 by way of a bevel gear 70. The supply of current to the electric motor is by way of a cable 72 which is guided in a sinusoidal configuration. Arranged in the housing 60 are supply rolls 74 and 76 for the roving material, and a supply container 78 for synthetic resin material. The roving is impregnated with synthetic resin in a trough 82 connected to the container 78 by way of a line 80, by the roving being passed below a roller 84 mounted in the trough. Issuing from the trough, the roving passes through a pair of guide rollers 86 and 88 and from there is wound on in a helicoidal fashion, by rotation of the winding member.

It will be understood that a plurality of rovings may be fed simultaneously by the feed means.

A control unit 90 which is shown in diagrammatic form in Figure 2 is provided for controlling the rotary speed of the tensioning members 2 and 4, the reciprocating movement of the feed means 8, and the winding tension.

Various control programs are provided for making hollow bodies of various shapes, or different winding patterns. The hyperboloid form of the hollow body produced is more marked, in proportion as the winding tension rises in relation to the tension in the threads of the winding core. The mean diameter of the hollow body can be determined by selection of the diameter of the members 2 and 4.

The method according to the invention is suitable in particular for making poles, for exam ple for carrying electric lines, telephone wires and the like.

Reference is directed to my copending Patent Application No. 6707/78 (Serial No.

1602205) which describes and claims a similar method and a winding machine for carrying out the described method.

Claims

WHAT I CLAIM IS:

1. A method of making a hollow body by winding material in thread or strip form on to a core, in which thread or strip lengths are secured in tension, and otherwise unsupported over their lengths, between two rotatable tensioning members to form the core, the two tensioning members being adjustably spaced apart by a distance corresponding to the axial length of the body to be produced and the core formed by the thread or strip lengths being incorporated into or forming part of the body being produced.

2. A method according to Claim 1, in which the threads or strips forming the core are secured in the region of the periphery of the two tensioning members, the tensioning members are rotated by a drive, and the winding material is fed thereto by a reciprocably movable feed means.

3. A method according to Claim 2, in which after the material has been wound onto the core, the winding operation is interrupted, and further threads or strips are tensioned between the tensioning members so that, after the winding operation is continued, the further threads or strips are enclosed between two wound layers, this operation being performed at least once.

4. A method according to any one of Claims 1 to 3, in which the winding operation is performed with synthetic resin-impregnated glass fibre rovings.

5. A method according to Claim 2, in which thread or strip lengths to be tensioned to form the core are fed to the tensioning members by means of the feed means for feeding the winding material, by the reciprocating movement of the feed means.

6. A method according to any one of Claims 1 to 5, in which a hollow body having a predetermined hyperboloid form is produced by control of the winding tension.

7. A winding machine for carrying out the method according to Claim 1, including two tensioning members which are mounted rotatably, coaxially and at an adjustable spacing from each other corresponding to the axial length of the body to be produced which are each connected to a rotary drive and which each have means for securing threads or strips, to be tensioned, between the two tensioning members, a thread or strip feed means, and means for guiding and reciprocating the feed means on a path extending substantially parallel to the axis of rotation of the tensioning members.

8. A winding machine according to Claim 7, wherein each tensioning member is secured on a shaft which is mounted radially and axially in a housing and which is connected to a drive and wherein an axially displaceable tensioning shaft is connected to the housing, the tensioning shaft being mounted in a frame portion of the winding machine.

9. A winding machine according to Claim 8, in which the distance between the oppositely disposed frame portions is adjustable for determining the axial length of the hollow body to be produced.

10. A winding machine according to Claim 7, in which numerous receiving openings are provided at the periphery of the tensioning members for receiving the threads or strips to be tensioned, wherein said openings are arranged in annularly extending rows, and rows are provided at different radial distances from the axis of rotation of the tensioning member.

11. A method of making a hollow body by winding material in thread or strip form on to a core, according to Claim 1, substantially as hereinbefore described with reference to the accompanying drawings.

12. A winding machine for carrying out the method according to Claim 1, substantially as hereinbefore described with reference to the accompanying drawings.