GB2185920A - Manufacture of waveguides - Google Patents

Abstract

A waveguide or other tubular element is made by winding a strip (1) onto an arbor (2), the strip (1) being pressed onto the arbor (2) at the point of winding by a pressure roller (3) mounted in a fixed position adjacent the arbor. The arbor (2) is supported for controlled lateral translational displacement in two mutually perpendicular directions (X,Y) in a plane perpendicular to the longitudinal axis (5) of the arbor (2) and is also displaceable angularly (w) about this axis. The translational and angular displacements (X,Y; w) of the arbor (2) are controlled so that the strip (1) is wound onto the arbor without substantial transverse displacement of the point of winding of the strip onto the arbor in each complete revolution of the arbor. <IMAGE>

Description

SPECIFICATION Manufacture of waveguides This invention relates to the manufacture of wave.

guidestand like tubular elements.

The invention is cirparticular, but not exclusive a pplicatibnrto the manufacture offlexible tubes, including flexible waveguides.

A known technique for the manufacture of tu bular elements including waveguides consists of winding a strip helically onto an arborthecrnss-sectional size and shape of which corresporsds to the desired cross section of the tubular element.

Before being wound upon the arborthe edges ofthe strip may be given a channel-section profile so that the overlapping edges ofthe strip interlock when the strip is wound into a tube. The preformed strip is presented to the arbor and pressed againstthe latter using profiled rollers operated by cams, so that the strip is formed into the shape ofthe arbor as the latter rotates.

In known methods of winding flexibletubes,the arbor on which the strip is wound is mounted upon a rotary spindle which also drives a cam plate carrying the cams and cam springs associated with the profiled forming rollers. Accurate control ofthe forming ofthe strip is difficult, particularly where the strip has to be formed into a tube of rectangular cross-sectional shape, for example in the manufacture of a flexible waveguide.

The present invention provides an improved method of making tubular element which affords a greater degree of control ofthe process of winding a strip onto an arbor.

According to the present invention there is provided a methodofmakingawaveguideorothertubular element by winding a strip onto an arbor, in which the strip is pressed onto the arbor at the point of winding ofthe strip and in which the arbor is supported for controlled lateral translational displacement in a plane perpendiculartothe longitudinal axisofthearborand is also displaceable angularly aboutthis axis,the translational and angular displacements of the arbor being controlledsothatthestrip is wound ontothe arbor withoutsubstantial transverse displacement of the point of winding ofthe strip onto the arbor in each complete revolution ofthe arbor.

Preferably, the lateraltranslational displacement of the arbor is effected by independent control of displacements in two mutuallyperpendicular directions in the said transverse plane perpendiculartothe axis ofthe arbor.

The invention also provides, in an.# other aspect, apparatus for manufacturing a waveguide or other tubular elements comprising an arbor, means for feeding a strip to;the arkor, and meansforeffecting controlied.lateraI;translational dlisplacement ofthe arbor inta transverse plane perpendicular to the longitudinal axis of the arbor and controlled angular cli#acerriiea.#t oftlhe arbor about said axis asthe strip is wound onto the arbor.

A pressure roller may be mounted in a fixed position adjacent the arborfor pressing the strip onto the arbor. The pressure roller may be formed with at least one ridge which cooperates with at least one groove in the arborto deform the wound strip, forming at least one ridgetherein.

The apparatus may be equipped with three motors for effecting, independently of each other, controlled translational displacement ofthe arbor in two mutually perpendicular directions in said transverse plane and angular displacement of the arbor. The motors may, for example, drive three respective coaxial shafts, the outermost one of which effects angular displacementto the arborwhilethetwo inner shafts effect the two components oftransverse displacement ofthe arbor.

By using a translationally and angularly displace ablearborwhich cooperates with a pressure roller, the necessity for cams, cam followers and spring for pressing the strip onto the arbor during winding is avoided, leading to considerable simplification of the structure and, potentially, a higherwinding speed.

The transverse and angular displacements of the arbor are preferablycomputer-controlled according to a programme allowing the movements of the arborto follow any desired cross-sectional profile of tubular element to be formed. Since the pressure roller is mounted in a fixed position, it is a relatively simple matter to interchange pressure rollers of different size and profile, so that in theory the apparatus can easily be adapted to the winding oftubular elements of small non-circular cross-section. The size and profile ofthe pressure roller will be chosen according to the size of the basic strip material to be wound, and the desired profile to be imparted to this strip, while the size ofthe arbor is chosen according to the size and profile ofthe tubular element to be formed.This enables the formed strip to be wound upon the arborwith virtually no damage or deformation.

The invention will befurtherdescribed, by way of example only, with reference to the purely diagrammatic drawings, in which: Figure lisa perspective view of apparatus for making awaveguideorothertubularelementaccording to one embodiment of the invention; Figures 2(i)-2(ix) are diagrammatic end views ofthe arbor and pressure roller ofthe apparatus of Figure 1, showing successive positions of the arbor during one winding cycle of a tubularelementof rectangular cross-section; Figure 3 is an end view of the displaceable support forthearboroftheapparatusshown in Figure 1, illustrating the drive arrangementforthe arbor; ; Figure 4 is a diagrammatic longitudinal section of the arbordrive,taken on line IV-IV in Figure 3,and Figure 5 is a schematic side elevation view showing the arrangement of component parts of a machine for windingtubularelementsaccordingtoan embodiment of the invention.

The drawings originally were informal and the print here reproduced is taken from a later filed formal copy.

The claims were filed later than the filing date within the period prescribed by Rule 25t1) of the Patents Rules 1982.

Atubularelementsuch as a flexible waveguide is made in accordance with the present invention by winding a strip 1 of any desired cross-section onto an arbor 2 the size and cross-section of which corresponds to the cross sectional profile of the tubular element to be formed.

Figure 2 illustrates the winding of a strip 1 onto a rectangular arbor2 for the formation of a flexible rectangular-sectionwaveguide.Asthestrip 1 is wound onto the arbor 2 it is pressed againstthe arbor 2 by a freely rotatable pressure roller3 arranged at the point of winding P of the strip 1 onto the arbor 2.

The pressure roller 3 has a fixed axis of rotation 4, while the axis 5 of the arbor 2 is displaceable laterally in a transverse plane perpendicular to the axis and angularly aboutthe said axis.

Specifically, with reference to Figure 2, the arbor 2 is arranged for independenttranslational displacement in two mutually perpendicular directions X and Yin a plane perpendicularto the axis 5 ofthe arbor and is alsocapableofindependentangulardisplacement w about the said axis.

The translational displacement in the two directions X, Yand the angulardisplacement ware controlled independently of each other by means ofthree electric motors 6, 7 and 8 each connected to a respective drive shaft 10 and 11 through a respective worm wheel drive 12,13 and 14. The shaft 9 for effecting translational displacement in the X direction is housed coaxiallywithin the shaft 1 Ofor effecting translational displacement in theY direction, and the shaft 10 is itself housed coaxiallywithin the shaft 12 which effects angular displacement w.

Respective shaft encoders (not shown) are coupled to each of the shafts 9,10 and 11 for providing positional feedback in a servo-control loop for each of the drive motors 6, 7 and 8. By a combination of controlled movements of the motors 6, 7 and 8 it is possible to effect independent translational displace mentofthe arbor 2 in the directions X and Y and angulardisplacements wabout the axis 5 and any combination of these, in order to position the arbor 2 relative to the pressure roller 3. Accordingly, by making a sequence of controlled translational and angular displacements of the fully mobile arbor 2, it is possible to wind the strip 1 onto the arbor 2 without effecting any displacement of the point of winding Por ofthe pressure roller3 located atthis point.

The sequence of displacements of the arbor2 relative to the pressure roller3 is illustrated in Figure 2.

Itwill be seenthat as the strip 1 is wound onto the shorter side ofthe rectangular-section arbor2, the arbor2 is displaced in the direction of this shorter side, that is, the direction Y (figure 1), without any rotation about its axis 5. When one corner of the arbor 2 has reached the pressure roller3 as shown in Figure 2(it), the arbor2 is displaced angularly about its axis 5, as indicated bythe arrow wand the axis 5 is simultaneously displaced in the direction X, with a reverse translational displacement in the direction Y, to allow the strip 1 to be wound around the cornerofthe arbor 2.The displacement of the arbor 2 in the direction X is thenreversedtobringthelongersideofthearb into contact with the pressure roller 3. Displacement of the arbor 2 in the direction Ythen winds the strip 1 onto the longer side ofthe arbor 2 as shown in Figure 2(iii). The winding process continues with the arbor 2 making a combination oftranslational and angular displacements as each corner of the arbor comes into contact with the pressure roller 3 so that the strip 1 is progressively wound around the entire arbor, the completion of one complete turn being shown at Figure2(ix).

In Figures 2(i)-2(ix), the directions of the translational displacements ofthe arbor2 indicated by arrowsX and Y correspond to the directions indicated in Figure 1, and angular displacements are indicated by arrows w. It will be seen thatthe angular displacements ofthe arbor 2 forthe winding of each complete turn ofthe strip 1 take place in four successive rotations through 900, occurring in steps atthewinding ofthestrip 1 around each corner ofthe rectangular-section arbor, as depicted in Figures 2(ii), 2(iv), 2(vi) and 2(viii).Each ofthese rotations is accompanied by a combined translational displacement of the axis 5 of the arbor 2 in directions X and Y, in orderto maintain the surface of the arbor 2, and therefore the strip 1, in contact with the fixed-axis pressure roller 3.

Figures 3and 4 show one practical version of a drive arrangement for translating the controlled rotations of the shafts 9 and 10 into corresponding translational displacements in the directions X and Y respectively, andfortranslating the controlled rotation of the drive shaft 11 into angular displacement wot the arbor 2.

Thearbor2issupported in a mounting plate 12 which is in turn supportedfortranslational displacement in the direction X on two parallel guide rods 13 carried by an intermediate plate 14 arranged behind the mounting plate 12 (Figure 1). The intermediate plate 14 is in turn arranged fortranslational sliding movement in the direction Y on two parallel guide rods 15 carried by a baseplate 16.

The baseplate 16 is directly connected to and driven bythe drive shaft 11 and imparts angular displacements wto the entire assembly.

The intermediate drive shaft 10 is coupled by means of a bevel gear 17 (Figure4) to atransverse drive shaft 18 supported bythe baseplate 16 for rotation about an axis parallel to the guide rods 15. The drive shaft 18 has a screw-threaded portion engaged by a travelling nut 19 which is attached to orformed integrally with the intermediate plate 14. Thus, rotation of the drive shaft 10 imparts rotationtothescrew-threaded drive shaft 18 which in turn causes translational displacement ofthe nut 19 and the intermediate plate 12 in the direction Y.

The inner drive shaft 9 is coupled to a transverse layshaft 20 through a bevel gear coupling 21, one of the bevel gears of which is splined to the layshaft 20 (Figure 4). The shaft 20 which is parallel to the guide rods 15 is rotatable in lugs 22 fixed tothe intermediate plate 14.The layshaft 20 is coupled through a further bevel gear coupling 23 to a drive shaft 24which is parallel to the guide rods 13 and which is supported for rotation about its axis in lugs carried bythe intermediate plate 12. The drive shaft 24 has a screw-th readed portion which is engaged by a travelling nut 25 affixed to orformed integrally with the mounting plate 12.Rotation of the drive shaft 9 imparts rotation through the bevel gears 21. the layshaft 20 and the bevel gears 23 to the screwthreaded drive shaft 24, which in turn causes displacement ofthe nut 25, andtherefore of the mounting plate 12, in the direction X, proportional to the rotation of the drive shaft 9.

The splined connection between the bevel gear coupling 21 and the layshaft 20 enables the bevel gear coupling to transmit drive to the layshaft 20 at any position along the layshaft 20, thereby permitting adjustment of the mounting plate 12 in the X direction by controlled rotation of the inner shaft 10 independently ofthe position of the mounting plate 12 in the Y direction controlled by rotation ofthe shaft 10. In order to effect pure rotation of the arbor mounting plate 12 unaccompanied by translational displacementthere- of,itisnecessarytodriveallthreeshafts9,10and11 in unison.Any combination of translational displacement and angular displacement of the arbor mounting plate 12 can be effected by appropriate independently controlled rotation of the drive shafts 9, 10 and 11, separately or in combination. The rotations of the drive shafts 9, 10 and 11 by means ofthe motors 6,7 and 8 is preferably effected under computer control, programmed according to the profile ofthe arbor 2 to be wound and preferably so arranged that the rate of winding of the strip 1 onto the arbor 2 remains substantially constant.

Figure 5 illustrates atypical arrangement ofthe component parts of a machine forwinding flexible tubular elements such as waveguides according to an embodiment of the invention. The drive arrangment illustrated diagrammatically in Figures 1,3 and 4 is housed in a drive head 26 from which the displaceable arbor 2 projects. The set of motors 6,7 and 8 is carried in a separate motor housing 27 attached to the drive head 26. The arbor movements effected by the drive head 26 are controlled from a controlled console28 which includes a microcomputer controlling the three drive motors 6,7 and 8 in order to effect the programmed sequential displacements of the arbor 2 as described previously.

The strip 1 to be wound on the arbor 2 is supplied from a spool feeder 29 through a diebox former30 which has interchangeable forming heads for preforming the strip into a cross-sectional profile as required. Forexample, channel-section edge profiles may be formed in the strip 1 if it is desired to interlock successive turns ofthe wound strip when forming the tube. Solder may be supplied to the preformed strip priorto winding from a supply spool feeder 31, for example when the successive wound turns of the strip are to be soldered togetherto form a flexible tube.

Alternatively, the spool feeder 31 may be used to deliver a wire which is interposed between successive turns ofthe interlocked strip to form a twistable tube.

A forming head 32 carries the pressu re roller 3 for pressing the preformed strip 1 onto the previously wound turn, forming it around the arbor 2, and performing a two-stage deformation process to complete the interlocking of successive turns.

As stated previously, the angular displacements of the arbor drive head 2, and its transverse displace ments vertically and horizontally, are controlled by the computer-controlled motors 6,7 and 8, in order to presentthe arbor 2 to the preformed strip ata predetermined linear winding speed which is independent of the cross-sectional profile ofthe arbor itself.

A detwist head 33 is provided to stabilise the wound strip as it leaves the arbor 2. Since the tube wound from the strip will naturally tend to assume a spiral shape, the head 10 introduces a reverse spiral to compensate forthis.

Subsequentto its formation the wound tube is passed through a solder zone 34 in which the tube is heated to cause the previously deposited solder to flow, when forming a non-twistableflexibletube.

Altern atively, the sol der zone cou Id be replaced by a heating zone which is used to heat the formed tu be in order to stress-relieve it.

The invention has been described, by way of example, in its application totheformation of a flexible waveguide. Itwill be appreciated that the invention is also applicable to the manufacture of tubular elements generally, whether flexible or inflexible, including tubes, pipes, springs and bellows.

Claims (11)

1. A method of making a waveguide or other tubular element bywinding a strip onto an arbor, in which the strip is pressed onto the arbor at the point of winding ofthe strip, and in which the arbor is supported for controlled lateral translational displacment in a plane perpendiculartothe longitudinal axis of the arbor and is also displaceable angularly about this axis,thetranslational and angulardisplacements ofthe arbor being controlled so thatthe strip is wound onto the arbor without substantial transverse displacement of the point of winding ofthe strip onto the arbor in each complete revolution ofthe arbor.

2. A method according to Claim 1, in which the lateral translational displacement of the arbor is effected by independent control of displacements in two mutually perpendicular directions in the said plane perpendicular to the axis ofthe arbor.

3. A method according to Claim 1 or Claim 2, in which thetranslational and angular displacements are so controlled thatthe strip is wound onto the arbor at a substantially uniform rate.

4. Apparatus for manufacturing a waveguide or othertubular element, comprising an arbor, means for feeding a strip to the arbor, and means for effecting controlled lateral translational displacement of the arbor in a plane perpendiculartothe longitudinal axis of the arbor and controlled angular displacement of the arbor about the axis as the strip is wound onto the arbor.

5. Apparatus according to Claim 4, including three motors for effecting, independently of each other, controlled translational displacement of the arbor in two mutually perpendicular directions in the said plane perpendicularto the axis ofthe arbor and angular displacement ofthe arbor.

6. Apparatus according to Claim 5, in which the three motors drive respective coaxial shafts, the outermost one of which effects angular displacement ofthe arborwhilethe inner two effectthetwo componentsoftranslational displacement of the arbor.

7. Apparatus according to Claim 6, in which the arbor is supported in a mounting plate supported for translational displacement in one direction on guides carried byan intermediate plate adjacent the mounting plate, the intermediate plate being arranged for translational displacement in the other direction on guides carried by a baseplate connectedto and driven bythe shaft which effects angular displacement of the arbor.

8. Apparatus according to any one of Claims 4to 7, including a pressure roller mounted in a fixed position adjacentthe arborfor pressing the strip onto the arbor.

9. Apparatus according to Claim 8, in which the pressure roller is formed with at least one ridge which cooperateswith atleast one groove in thearborto deformthewoundstrip,forming at least one ridge therein.

10. A method of making a waveguide or other tubular element, substantially as herein described with reference to, and as shown in, the accompanying drawings.

11. Apparatusformanufacturing a waveguide or othertubular element, substantially as herein described with reference to, and as shown in, the accompanying drawings.