GB2159081A - Method of forming flanges on a tube - Google Patents

Abstract

A method of forming first and second flanges on a tube for example on upright tube (11) of a clothes dryer, the first flange being formed at the end of the tube (11) and the second flange being formed at a position spaced from the end thereof, said method including the steps of gripping the tube with a clamping means (30) with a length (33) of the tube (11) projecting from the clamping means (30), inserting a mandrel (36) into the end of the tube (11) to bring a forming part (37) of the mandrel (36) into engagement with said end, moving the mandrel (36) further into the tube (11) a first distance axially of the tube (11) to cause the end of the tube to be deformed into a recess (38) in the forming part (37) of the mandrel (36) to form said first flange, preventing further deformation of the end of the tube (11), moving the mandrel (36) axially further into the tube (11) a second distance, to cause a portion of the projecting length (33) of the tube (11) adjacent the clamping means (30) to be deformed into a recess (34) of the clamping means (30) to form said second flange, and withdrawing the mandrel (36). <IMAGE>

Description

SPECIFICATION Method of forming flanges on a tube This invention relates to a method of forming first and second flanges on a tube, the first flange being formed at the end of the tube, and the second flange being formed at a position spaced from the end of thetube.

More particularly, but not exclusively, the invention relates to a method of forming first and second outwardly extending flanges on a tube, and locating a collartherebetween such as a collarforsupporting radially extending arms or stays of a rotary clothes dryer.

According to a first aspect of the invention, we provide a method of forming first and second flanges on a tube, the first flange being formed at the end of the tube and the second flange being formed at a position spaced from the end thereof, said method including the steps of gripping the tube with a clamping means with a length of the tube projecting from the clamping means, inserting a mandrel into the end of the tube to bring a forming part of the mandrel into engagement with said end, moving the mandrel further into the tube a first distance axially of the tube to cause the end of the tube to be deformed into a recess in the forming part of the mandrel, to form said first flange, preventing further deformation of the end ofthetube, moving the mandrel axially further into the tube a second distance, to cause a portion of the projecting length of the tube adjacent the clamping means to be deformed into a recess of the clamping means to form said second flange, and withdrawing the mandrel.

Preferably, the recess in the forming part of the mandrel has an inital part closest to the tube of a curved configuration to encourage deformation of the end of the tube as the mandrel is moved said first axial distance, and an abutment surface with which the end of the tube engages to prevent further deformation of said tube end.

The recess in the clamping means may also be of curved configuration to encourage the portion of the projecting length of the tube to be deformed into the recess.

Surprisingly, it has been found that contrary to what would be expected, the projecting length of the tube between said portion and the flanged end thereof does not tend to buckle or to be deformed outwardly as the mandrel is moved its second axial distance, but the second flange is formed.

The invention is particularly applicable to forming outwardly extending flanges between which a collar may be located. Accordingly, if desired, the method may include the step of receiving on the mandrel prior to insertion of the mandrel into the tube, a collar whereby as the mandrel is inserted, the collar is received on the projecting end of the tube, and the first and second flanges are formed either side of the collar to locate the collar therebetween.

Alternatively, the collar may be received on the projecting end of the tube prior to insertion of the mandrel into the end of the tube. In either case, once the flanges are formed, it will be appreciated that provided there is adequate clearance, the collar will be free to rotate about the axis of the tube and the flanges will provide stops for the collar which will not impede rotation of the collar, thereby reducing wear on the engaging surfaces as the collar rotates.

This is particularly important in arrangements where the tube is metal, for example aluminium or steel, and the collar comprises a plastics moulding.

The clamping means may comprise two or more clamping members which can be moved apart relatively to permit the tube to be received therebetween, and which can be moved together to grip the tube therebetween.

Preferably, each clamping member has a partcylindrical rebate which, when the clamping members are moved together to grip the tube, provide a generally cyclindrical opening in which the tube is gripped.

The invention is particularly applicable to coih ths dryers of the rotary type comprising an upright tube which is secured relative to the ground, a collar rotatably mounted at the upper end of the tube in a fixed position axially of the tube, which collar supports a plurality of radially extending stays or arms, a further collar movable up and down along the tube which supports a plurality of radially extending arms or stays respectively, the arms being pivotally secured to the stays and means being provided to retain the movable collar for rotation in a fixed position axially of the tube, for use. Such a clothes dryer will hereinafter be referred to as "of the kind specified".

According to a second aspect of the invention we provide a method of forming a flange on a tube of a clothes dryer of the kind specified for constraining axial movement of the collar at the upper end of the tube, said method comprising the steps of gripping the tube with a clamping means with a length of the tube projecting from the clamping means, inserting a mandrel into the end of the tube to bring a forming part of the mandrel into engagement ç ith said end, moving the mandrel further into the tube a first distance axially of the tube to cause the end of the tube to be deformed into a recess in the forming part of the mandrel to form a first flange.

Thus when the collar is received on the tube, the collar is prevented from sliding axially from the end of the tube by said first flange.

Preferably the method of the second aspect of the invention includes the steps of preventing further deformation of the end of the tube, receiving the collar on the tube, and moving the mandrel axially further into the tube a second distance to cause a portion of the projecting length of the tube adjacent the clamping means to be deformed into ? recess of the clamping means to form a second flange, and withdrawing the mandrel.

Thus the collar is prevented from sliding axially away from the end of the tube by the second mentioned flange.

According to a third aspect of the invention we provide a method of forming a flange on a tube of a clothes dryer of the kind specified for constraining axial movement of the collar at the upper end of the tube, said method comprising the steps of gripping the tube with a clamping means with the length of the tube projecting from the clamping means, inserting a mandrel into the end of the tube until the end of the tube is in engagement with the mandrel, moving the mandrel axially further into the tube to cause a portion of the projecting length of the tube adjacent the clamping means to be deformed into a recess of the clamping means to form a flange, and withdrawing the mandrel.

Preferably the flange so formed is spaced from the end of the tube.

The end of the tube may be brought into engagemenu with a forming part of the mandrel prior to the flange being formed, so that as the mandrel is moved into the tube, the end of the tube is deformed into a recess in the forming part of the mandrel to form a flange at said end.

The method may include the steps of receiving the collar at the end of the tube prior to both the flanges being formed.

The methods according to the second and third aspects of the invention may include any of the method steps of the method according to the first aspect of the invention.

According to a fourth aspect of the invention, we provide a clothes dryer of the kind specified wherein the upright tube has at least one flange formed thereon by a method according to the second or third aspects of the invention. Afirstflange may be formed at the end of the tube and a second flange may be formed spaced from the end of the tube, the collar at the upper end of the tube being located between the first and second flanges.

Preferably, each of the collars has outwardly extending ears to which the arms or stays are pivotally mounted, so that when not in use, the clothes dryer can be simply folded by moving the further collar relative to, i.e. towards, or more usually away from, the fixed collar to bring the arms or stays into generally parallel relationship with the tube.

The means to retain the further collar in its fixed axial position may comprise a locking means separate from, or integral with the collar which is movable along the tube, the locking means having to engage the tube, to retain the movable collar in a desired position. Alternatively, said means may comprise a retaining pin or the like which passes through aligned openings in the wall of the upright tube with which the further collar engages.

However, in a preferred arrangement, each of the collars has a bracket engaging formation with which a bracket is, in use, secured to prevent the movable collar moving towards or away from the fixed collar, in use, so that the two collars can rotate together rather than independently about the tube.

Preferably the fixed and movable collars are identical plastics mouldings, although different mouldings can be provided if required.

Usually, in a clothes dryer of the kind specified, plastic or other flexible elements extend between the arms andlor stays on which the clothes may be draped for drying.

Any suitable means may be provided to secure the tube relative to the ground. For example, the lower end of the tube may be received in a further tube which is set in concrete or otherwise embedded in the ground.

The invention will now be described with the aid of the accompanying drawings, wherein: Figure 1 shows diagrammatically a general arrangement of a clothes dryer having an upright tube on which first and second flanges are formed by a method in accordance with the invention: Figure 2 shows a mandrel and clamping means for use in the method according to the invention; Figure 3 shows a longitudinal sectional view of part of a tube formed with first and second flanges by a method in accordance with the invention, with a collar located between the flanges.

Referring first to Figure 1, a clothes dryer 10 comprises an upright tube 11 which, in the present example is a thin walled steel or aluminium tube, the lower end 12 of which is received in a further tube 13 which has a base 14 and is embedded in concrete 15 in the ground 16. Of course any other arrangement for securing the tube relative to the ground may be provided. The tube 11 may be rotatable in the tube 13, or may be fixed as required.

Atthe upper end 17 of thetube 11, a collar 18 is mounted for rotation but its position is fixed axially of the tube, by first and second flanges (not seen in Figure 1)formed by a method as hereinafter described.

Afurther collar 19 is provided which is rotatable and movable up and down the tube 11, but the axial position of the collar 19 can be fixed, in use, by a locking means, although the collar 19 would still be rotatable.

The locking means may comprise a sleeve, such as shown at 20, which has spring biased elements frictionally engaged with the tube 11, and can be released by a lever 21. Alternatively, the tube 11 may be provided with one or a series of openings along the tube in which a pin is received.

However, in a preferred embodiment (not shown in Figure 1) each ofthe collars 18 and 19 have formations to receive a bracket which retains the collar 19 in position. Thus the collars 18 and 19 would rotate as a unit, rather than independently.

Each of the collars 18 and 19 have a plurality of outwardly extending ears, some of which are seen at 22. The ears 22 on collar 19 support three radially extending arms 23 which, as shown in an "in use" position also extend upwardly from the tube 11.

However, the arms 23 are pivotable relative to the collar 19 and so for stowage, or otherwise when not in use, the arms 23 can be pivoted further upwardly until they are generally parallel with the tube 11 by moving the collar 19 downwardly. More than three arms 23 may be provided if required, or even only two.

The ears 22 of the collar 18 support three stays 24 which are pivotally secured to the arms 23 and thus, in use, retain the arms 23 in the position shown.

However, the stays 24 are also pivotable relative to the collar 18 so as not to inhibit folding of the arms 23 when the dryer 10 is not in use. Of course, when the arms 23 are folded so as to be generally parallel to the tube 11, the stays 24 will also be generally parallel to the tube 11.

Flexible elements E, such as plastic or plastics covered strings or wires, extend between the arms 23 so that the clothes may be draped over the elements E.

In an alternative arrangement, the arms may be pivoted to the collar 18 and the stays 24to collar 19, and the elements E may, instead of or in addition to extending between the arms 23, extend between the stays 24 and/or arms and stays.

As mentioned above, the collars 18 and 19 are rotatable about the tube 11 to facilitate the action of wind and warm air on the clothes as they are draped.

In each of the embodiments described, it is necessary to locate collar 18 in its position at the upper end of the tube 11, and the preferred method is by forming first and second flanges on the tube as will now be explained with reference to Figure 2.

The tube 11 is first gripped by a clamping means 30 which in the present example comprises a pair of clamping members 31 which each have a semicircular rebate 32 which together form a cylindrical opening in which the tube 11 is received. In an alternative arrangement, more than two clamping members 31 may be provided each with a partcylindrical rebate which together form a generally cylindrical opening for the tube 11.

The members 31 are movable relatively towards one another to grip the tube 11 as shown, with a length 33 of the tube projecting from the clamping means 30.

In another arrangement, the clamping means 30 may comprise a one-piece member with a cylindrical opening with, for example, transversely movable elements such as screws which are engageable with the tube 11 to grip the tube.

In each case, the clamping means 30 is provided with an annular recess 34 of curved configuration, formed at the mouth ofthe opening provided by the clamping member or members 31, for a purpose hereinafter explained.

When the tube 11 is gripped by the clamping means 30, a mandrel 36 is inserted into the end of the projecting length of the tube 11 until a forming part 37 of the mandrel engages the end of the tube 11. The forming part 37 of the mandrel 36 comprises an annular recess 38 having a first part 39 nearest the tube 11, of curved configuration, and a second part 40 which comprises an abutment surface which is generally parallel to the axis A of the tube 11.

When the mandrel 36 is received in the end of the tube 11, with the end of the tube engaging the forming part 37, the mandrel 36 is moved further inwardly of the tube along the axis A, a first distance to cause the end of the tube to be deformed into the recess 38 until the end of the tube 11 engages the abutment surface 40, so that further deformation of the end of the tube is prevented.

The mandrel 36 is then moved further inwardly of the tube 11 along axis A a second distance. This causes a portion 41 of the tube length 33 adjacent the recess 34 to be deformed into the recess 34 at the mouth of the opening.

It has been found, surprisingly, that the projecting length 33 of the tube 11 between clamping means 30 and the forming part 37 of the mandrel 36, does not bulge outwardly, buckle or otherwise become deformed but simply, the portioln 40 is deformed into the recess 34.

It will be appreciated that the end of the tube 11 which is deformed into the recess 38 comprises a first flange, whilst the portion 40 of the tube 11 which is deformed into the recess 34 in the clamping means 30, comprises a second flange.

The collar 18 of the clothes dryer 10, shown in Figure 1, is either received on the projecting length 33 of the tube 11 before the mandrel 36 is inserted into the end of the tube, or the collar 18 is received on the mandrel 36 prior to the mandrel being inserted into the end of the tube, so that as the mandrel is inserted, the collar 18 will be slid over the tube 11 into its final position. Thus, once the first and second flanges are formed on the tube as hereinbefore described, the collar 18 will be tripped bewee- the two flanges and thus located in a position fixed axially of the tube, whilst rotation of the collar 18 about the axis A would be permitted, provided that clearance between the first and second flanges is adequate.

Referring now to Figure 3, there is shown a side view of a collar 18 which is thus located in position between a first flange indicated at 45, and a second flange indicated at 46.

Ears 22 of the collar 18 are clearly shown, each ear 22 having an opening 47 in which a pivot pin or the like to enable the stays 24 (or arms) to be pivotally secured to the ears 22, can be received.

The ears 22 are arranged in pairs and such a pivot pin would extend between a pair of ears 22, to pivotally mount one stay 24 (or arms) in position.

The collar 18 is a plastics moulding but, as the flanges 45 and 46 extend entirely around the tube 11, as the collar 18 rotates about axis A, there will not be undue wear of the collar 18 where it contacts the harder metal tube.

Also shown on the collar 18 in FiGlrr- ? 'S ais a formation 49 which, in use. recehtee -r wf a bracket by which the collar 13 8 is secured to {.ie collar 19 when the dryer 10 is in use.

Preferably, the collar 19 is of identica! ,,nfigura- tion to the collar 1 8 so that it is not necessary to provide two separate tools for the production of the collars 18 and 19.

Many modifications are possible to the method or forming flanges, and the clothes dryer described, without departing from the scope of the invention.

For example, although as shown in Figure 2, the mandrel 36 terminates at a tapered nose 50 which facilitates insertion of the mandrel 36 into the end of the tube 11, if desired a longer or shorter 'ring portion, which need not have a tapered nose, could be provided.

The mandrel may be moved along axis A under the power of a hydraulic ram or could merely be struck by a hammer or the like to cause deformation of the tube 11 at the end thereof to form the first flange 45, and to form a second flange 46.

The collars 18 and 19 need not comprise identical plastics mouldings as described, but could be made of other materials if required and could be different from one another where this is desired.

Although as seen in Figure 2, the rebate 34 in the clamping means 30 is concave in configuration, of course this could be convex, or of any other configuration to encourage the deformation of portion 41, and to provide any desired form of second flange 46.

If desired, the rebate 38 in the forming part 37 of the mandrel 36 need not be of the configuration shown, but could be of other configurations if required.

The method described with particular reference to Figure 2 has wider application than merely providing flanges on a tube of a clothes dryer, and could be used in any application where it is required to provide first and second flanges on a tube, the first flange being at the end of the tube and the second flange being spaced from the end of the tube. In this event, the first flange 45 need not extend outwardly but could be arranged to extend inwardly, although it would be necessary in such an arrangement to manufacture the mandrel in two parts to enable the mandrel 36 to be subsequently withdrawn from the end of the tube.

The first flange 45 may extend further outwardly or not so far outwardly, as the first flange shown.

The mandrel 36 is preferably made of a hard material, such as steel, and may be fabricated, cast or otherwise made as desired.

The clamping members 31 may be moved together in a vice to grip the tube 11, or under the action of suitable power means, such as a hydraulic ram. Only one or both of the members 31 may actually move.

By changing the configuration of the recess 38 of the mandrel 36 and/or the recess 34 in the clamping means 30, a flange or flanges may be provided which are not continuous around the wall of the tube but comprise a series of flange sections spaced apart by gaps.

Although as described, the collar 18 of the dryer is constained against axial movement along the tube 11 by first and second flanges, in a clothes dryer according to the second and third aspects of the invention defined above, only a first or a second flange may be provided to constrain the collar against axial movement towards or away from the end of the tube respectively, further means being provided, such as any suitable stop, to prevent movement of the collar axially of the tube away from or towards the end of the tube. However, it is preferred that first and second flanges are provided, as described above.

Claims (26)

1. A method of forming first and second flanges on a tube, the first flange being formed at the end of the tube and the second flange being formed at a position spaced from the end thereof, said method including the steps of gripping the tube with a clamping means with a length of the tube projecting from the clamping means, inserting a mandrel into the end of the tube to bring a forming part of the mandrel into engagement with said end, moving the mandrel further into the tube a first distance axially of the tube to cause the end of the tube to be deformed into a recess in the forming part of the mandrel, to form said first flange, preventing further deformation of the end of the tube, moving the mandrel axially further into the tube a second distance, to cause a portion of the projecting length of the tube adjacent the clamping means to be deformed into a recess of the clamping means to form said second flange, and withdrawing the mandrel.

2. A method according to claim 1 wherein the recess in the forming part of the mandrel has an initial part closest to the tube of a curved configuration to encourage deformation of the end of the tube as the mandrel is moved said first axial distance, and an abutment surface with which the end of the tube engages to prevent further deformation of said tube end.

3. A method according to claim 1 or claim 2 wherein the recess in the clamping means is of curved configuration to encourage the portion of the projecting length of the tube to be deformed into the recess.

4. A method according to any one of claims 1 to 3 which includes the step of receiving on the mandrel prior to insertion of the mandrel into the tube, a collar whereby as the mandrel is inserted, the collar is received on the projecting end of the tube, the first and second flanges being formed either side of the collar to locate the collar therebetween.

5. A method according to any one of claims 1 to 3 wherein a collar is received on the projecting end of the tube prior to insertion of the mandrel into the end of the tube.

6. A method according to any one of claims 1 to 5 wherein the tube is metal and the collar comprises a plastics moulding.

7. A method according to any one of claims 1 to 6 wherein the clamping means compris^-* - - more clamping members which can be moved apart relatively to permit the tube to be receivedthernbe tween, and which can be moved together to grip the tube therebetween.

8. A method according to claim 7 wherein each clamping member has a part-cylindrical rebate which, when the clamping members are moved together to grip the tube, provide a generally cylindrical opening in which the tube is gripped.

9. A method of forming a flange on a tube of a clothes dryer of the kind specified for constraining axial movement of the collar at the upper end of the tube, said method comprising the steps of gripping the tube with a clamping means with a length of the tube projecting from the clamping means, inserting a mandrel into the end of the tube to bring a forming part of the mandrel into engagement with said end, moving the mandrel further into the tube a first distance axially of the tube to cause the end of the tube to be deformed into a recess in the forming part of the mandrel to form a first flange.

10. A method according to claim 9 which includes the steps of preventing further deformation of the end of the tube, receiving the collar on the end of the tube and moving the mandrel axially further into the tube a second distance to cause a portion of the projecting length of the tube adjacent the clamping means to be deformed into a recess of the clamping means to form a second flange, and withdrawing the mandrel.

11. A method of forming a flange on a tube of a clothes dryer of the kind specified for constraining axial movement of the collar at the upper end of the tube said method comprising the steps of gripping the tube with a clamping means with a length of the tube projecting from the clamping means, inserting a mandrel into the end of the tube until the end of the tube is in engagement with the mandrel, moving the mandrel axially further into the tube to cause a portion of the projecting length of the tube adjacent the clamping means to be deformed into a recess of the clamping means to form a flange, withdrawing the mandrel.

12. A method according to claim 11 wherein the flange so formed is spaced from the end of the tube.

13. A method according to claim 11 or claim 12 wherein the end of the tube is brought into engagement with a forming part of the mandrel prior to the flange being formed, so that as the mandrel is moved into the tube, the end of the tube is deformed into a recess in the forming part of the mandrel to form a flange at said end.

14. A method according to claim 13 which includes the step of receiving the collar on the end of the tube prior to both of the flanges being formed.

15. A method according to any one of claims 9 to 14 which includes any of the method steps of any one of claims 1 to 8.

16. A method of forming a first and/or a second flange on a tube substantially as hereinbefore described with reference to the accompanying drawings.

17. A clothes dryer of the kind specified wherein the upright tube has at least one flange formed thereon by a method according to any one of claims 9to 16.

18. A clothes dryer according to claim 12 having a first flange provided at the end of the tube, and a second flange spaced from the end of the tube, the collar at the upper end of the tube being located between the first and second flanges.

19. A clothes dryer according to claim 17 or claim 18 wherein each of the collars has outwardly extending ears to which the arms or stays are pivotally mounted.

20. A clothes dryer according to claim 19 wherein when the further collar is moved relative to the fixed collar axially of the tube, the arms or stays are brought into generally parallel relationship with the tube.

21. A clothes dryer according to any one of claims 17 to 20 wherein the means to retain the further collar in its fixed axial position comprises a locking means separate from, or integral with the collar which is movable along the tube, the locking means having means to engage the tube, to retain the movable collar in a desired axial position.

22. A clothes dryer according to any one of claims 17 to 20 wherein the body means to retain the further collar in its fixed axial position comprises a retaining pin which passes through aligned openings in the wall of the upright tube with which the further collar engages.

23. A clothes dryer according to any one of claims 17 to 20 wherein each of the collars has a bracket engaging formation with which a bracket is, in use, secured to prevent the movable collar moving towards or away from the fixed collar.

24. A clothes dryer according to any one of claims 17 to 23 wherein the fixed and movable collars are identical plastics mouldings.

25. A clothes dryer substantially as hereinbefore described with reference to and as shown in the accompanying drawings.

26. Any novel feature or combination of novel features described herein and/or as shown in the accompanying drawings.