TECHNICAL FIELD:

The present disclosure relates to the field of manufacturing technology. Particularly, but not exclusively, the present disclosure relates to an apparatus for forming or thickening a tube. Further embodiments of the present disclosure discloses apparatus and process for thickening the tube at its brim.

BACKGROUND OF THE DISCLOSURE:

A tube is a long hollow cylinder made of materials such as metal, plastic or composites. The tubes may be used in various applications in the field of domestic, medical, fuel gas distributions, automotive and other applications including air conditioning and refrigeration. For example in the automotive applications such as two-wheelers, tubes may be used in frames, seating systems, fuel delivery components and automotive link arms require tubes to be welded in series to create an integrated frame. The tubes may be welded using a various known welding methods such as MIG welding, flux-cored arc welding, TIG welding, stick welding etc. depending upon the material of the tube and the size of the tube. Welding is a process of joining parts together by heating the surfaces to the point of melting. In the process of welding different zones may be formed such as fusion zone, weld interface, heat affected zone etc. The fusion zone is a section of the material that is present after an object has been welded. The fusion zone begins and ends at the portion of the material that have been coalesced. This zone will have a chemical composition that is a mixture of the substrate being welded together and any additional filler material that may have been used.

The weld interface is a region composed of an unmixed zone of weld. The heat affected zone (HAZ) is the area of the base material which is not melted but its microstructure and properties are altered by the welding. The fusion zone and the HAZ acts a stress raiser zone in the material. The stress raiser zones increase stress concentration factor, further reducing the fatigue behavior of the welded connection. To avoid these stress raiser zones the tubes of uniform higher thickness can be used, or tubes thickened only at its free ends can be used in the automotive applications. The tubes of higher uniform thickness can be used in the application, but it adds unnecessary weight to the overall assembly. The latter approach i.e., the use of tubes thickened at the ends ensures overall weight reduction of the entire assembly as only the end parts which are to be welded are thickened.

The conventional process known in art for producing variable thickness tubes are flexible rolling, swage auto-frettage process, tube drawing using position controlled mandrel methods, extrusion with special die setup and also internally and externally upsetting ends of the tube. The ends of the tubes can be thickened using the above mentioned process. The above said process have several restraints such as higher investment in tooling and/or low productivity due to increased cycle time.

The present disclosure is directed to overcome one or more limitations stated above.

SUMMARY OF THE DISCLOSURE

One or more shortcomings of the conventional process are overcome by process as claimed and additional advantages are provided through the provision of processes as claimed in the present disclosure.

Additional features and advantages are realized through the techniques of the present disclosure. Other embodiments and aspects of the disclosure are described in detail herein and are considered a part of the claimed disclosure.

In one non-limiting embodiment of the disclosure, an apparatus for thickening a tube at its brim is disclosed. The apparatus includes a first support member, that is configured to rigidly support a first longitudinal surface of the tube along its length excluding one or both ends of the tube. The apparatus further includes a second support member configured to rigidly support a second longitudinal surface of the tube along its length excluding one or both ends of the tube. The apparatus also includes a punch driven by an external power source, wherein the punch is configured to exert force on one or both ends of the tube. The application of force by the punch plastically deforms the ends of the tube, thereby thickening the tube at one or both ends.

In an embodiment of the disclosure, the apparatus includes a block driven by a first external power source, wherein a longitudinal force on the block is configured to impart lateral outward movement on the second support member to further support the second longitudinal surface of the tube.

In an embodiment of the disclosure, the block is wedge-shaped.

In an embodiment of the disclosure, the first support member includes an outer tube holder and an outer insert. Also, the first support member is driven by a second external power source.

In an embodiment of the disclosure, the outer tube and the outer insert are joined through at least one of mechanical joining and thermal joining.

In an embodiment of the disclosure, the ends of the outer insert are chamfered, such that the ends of of the outer insert define a portion of the die for the plastic deformation of one or both ends of the tube.

In an embodiment of the disclosure, the second support member includes an inner tube holder and an inner insert. The inner tube holder and the inner insert are joined through at least one mechanical joining or thermal joining process.

In an embodiment of the disclosure, the one or both ends of the inner insert are chamfered, such that the ends define a portion of the die for plastic deformation of the ends of the tube.

In an embodiment of the disclosure, the shape of the inner tube holder corresponds to shape of the block.

In an embodiment of the disclosure, the external power source is a hydraulic drive.

In an embodiment of the disclosure, the first support member and the second support member are chamfered apart at the either extreme ends to be in non-contact with the tube’s brim.

In an embodiment of the disclosure, the first longitudinal surface of the tube is the outer surface of the tube and the second longitudinal surface of the tube is inner surface of the tube.

In another non-limiting embodiment of the disclosure, a tube is formed using the apparatus. The tube including, a body portion and a brim portion at one or both ends of the of the body portion. The brim portion at one or both ends of the body portion is such that, thickness of the brim portion of the tube is greater than thickness of the body portion of the tube.

In an embodiment of the disclosure, the body portion of the tube is of uniform thickness.

In an embodiment of the disclosure, the thickness of the brim portion of the tube is may or may not uniformly vary from body portion thickness to 20-30% greater than the body portion thickness.

In another non-limiting embodiment of the disclosure, a process of thickening a tube at its brim is disclosed. The process includes supporting by a first support member along the first longitudinal surface of the tube along its length excluding one or both the ends of the tube, supporting by a second support member along the second longitudinal surface of the tube along its length excluding one or both ends of the tube and compressing by a punch on one or both ends of the tube. The application of force by the punch plastically deforms the ends of the tube, increasing thickness of the tube at one or both ends.

In an embodiment of the disclosure, the process further includes moving the second support member laterally outwards to support the central portion of the inner surface of the tube rigidly. The block used in the process can be wedge shaped.

In an embodiment of the disclosure, the first support member, the punch and the block are driven by an external hydraulic power source.

It is to be understood that the aspects and embodiments of the disclosure described above may be used in any combination with each other. Several of the aspects and embodiments may be combined together to form a further embodiment of the disclosure.

The foregoing summary is illustrative only and is not intended to be in any way limiting. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features will become apparent by reference to the drawings and the following detailed description.

BRIEF DESCRIPTION OF THE ACCOMPANYING FIGURES

The novel features and characteristic of the disclosure are set forth in the appended claims. The disclosure itself, however, as well as a preferred mode of use, further objectives and advantages thereof, will best be understood by reference to the following detailed description of an illustrative embodiment when read in conjunction with the accompanying figures. One or more embodiments are now described, by way of example only, with reference to the accompanying figures wherein like reference numerals represent like elements and in which:

FIG.1 illustrates a pictorial view of an apparatus used for thickening a tube at its brim, in accordance with an embodiment of the present disclosure.

FIG.2 illustrates an isometric view of one half of an inner tube holder assembly, in accordance with an embodiment of the present disclosure.

FIG.3 illustrates an isometric view of one half of an outer tube assembly, in accordance with an embodiment of present disclosure.

FIG.4a and FIG.4b illustrates cross-sectional) views of the tube that is firmly held between first and the second support member for thickening on one or both ends, in accordance with an embodiment of the present disclosure.

The figures depict embodiments of the disclosure for purposes of illustration only. One skilled in the art will readily recognize from the following description that alternative embodiments of the structures and methods illustrated herein may be employed without departing from the principles of the disclosure described herein.

DETAILED DESCRIPTION

The foregoing has broadly outlined the features and technical advantages of the present disclosure in order that the detailed description of the disclosure that follows may be better understood. Additional features and advantages of the disclosure will be described hereinafter which form the subject of the claims of the disclosure. It should be appreciated by those skilled in the art that the conception and specific embodiment disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present disclosure. It should also be realized by those skilled in the art that such equivalent processes do not depart from the spirit and scope of the disclosure as set forth in the appended claims. The novel features which are believed to be characteristic of the disclosure, both as to its organization and method of operation, together with further objects and advantages will be better understood from the following description when considered in connection with the accompanying figures. It is to be expressly understood, however, that each of the figures is provided for the purpose of illustration and description only and is not intended as a definition of the limits of the present disclosure. It will be readily understood that the aspects of the present disclosure, as generally described herein, and illustrated in the figures, can be arranged, substituted, combined, and designed in a wide variety of different configurations, all of which are explicitly contemplated and make part of this disclosure.

Embodiments of the present disclosure discloses an apparatus for thickening a tube at its brim, particularly tubes used in components of automobile. The apparatus includes a first support member, which is configured to rigidly support a first longitudinal surface of the tube along its length excluding one or both ends of the tube. The first support member may be driven by a second external power source. The apparatus further includes a second support member, which is configured to rigidly support a second longitudinal surface of the tube along its length excluding the ends of the tube.

In an embodiment, the apparatus includes a punch, driven by an external power source. The punch may be configured to exert force on either ends of the tube. The application of the force by the punch plastically deforms the ends of the tube, thickening the tube at its brim. In an embodiment, the tube may get thickened at one or both ends of the tube. The apparatus also includes a block that may be driven by a first external power source. The block is driven by a first power source, which imparts longitudinal force on the block. The longitudinal force on the block is configured to impart lateral outward movement on the second support member. The movement causes the second support member to move towards the second longitudinal surface, so as to rigidly support the second longitudinal surface of the tube. Further, the first support member includes an outer tube holder and an outer insert. The outer tube holder and the insert are joined through at least one of the mechanical joining and thermal joining. The ends of the outer insert may be chamfered such that the ends of the outer insert define a portion of the die for plastic deformation of the ends of the tube.

Similarly, the second support member also includes an inner tube holder and an inner insert, which are joined through at least one of mechanical joining such as nuts and bolts or thermal joining such as welding. The ends of the inner insert are chamfered, such that they define a portion of die for plastic deformation of the ends of the tube. Also, the inner tube holder corresponds to the shape of the block which may be wedge shaped or any of such shapes.

The tube formed using the apparatus comprises a body portion and a brim portion at one or both ends of the body portion. The brim portion at one or both ends of the body portion is such that, the thickness of the brim portion of the tube is greater than the thickness of the body portion of the tube. The body portion of the tube may be of uniform thickness and the portion of the brim on either ends of the body may be having an increased thickness than that of the body portion.

Subsequently, the tube is supported by the first support member at the central portion along the first longitudinal surface. Further, the tube is supported by the second support member at the central portion along the second longitudinal surface. The free ends on either sides of the tube are not supported; this portion forms the material to be deformed in the die. A moving block driven by the first external drive exerts a laterally outward force on the second support member to support the central portion of the second longitudinal surface of the tube rigidly. The first support member, the punch and the block may be driven by an external hydraulic power source to perform the required process.

The terms “comprises”, “comprising”, or any other variations thereof used in the specification, are intended to cover a non-exclusive inclusion, such that an assembly that comprises a list of components or steps does not include only those components or steps but may include other components or steps not expressly listed or inherent to such setup or method. In other words, one or more elements in an assembly proceeded by “comprises… a” does not, without more constraints, preclude the existence of other elements or additional elements in the assembly.

Henceforth, the present disclosure is explained with the help of one or more figures of exemplary embodiments. However, such exemplary embodiments should not be construed as limitation of the present disclosure.

The following paragraphs describe the present disclosure with reference to FIGS.1, 2, 3, 4a and 4b. In the figures, the same element or elements which have similar functions are indicated by the same reference signs.

FIG.1 is an exemplary embodiment of the present disclosure, illustrating pictorial view of an apparatus (100) used for thickening a tube (101) on one or both ends. As shown in FIG.1, the apparatus (100) includes a first support member (102), a second support member (103), a punch (104) and a block (105). The tube (101) is held firmly between the first support member (102) and the second support member (103), on the longitudinal surface of the tube (110 and 111). The first support member (102) is configured to rigidly support the tube (101) on the first longitudinal surface (110). The first longitudinal surface (110) of the tube (101) may be the outer surface of the tube (101). Further, the second support member (103) is configured to rigidly support the tube (101) on the second longitudinal surface (111). The second longitudinal surface (111) of the tube (101) may be the inner surface of the tube (101). The block (105) as shown in the FIG.1 is configured to impart a lateral outward movement on the second support member (103). The block (105) is driven by a first external power source in the longitudinal direction, imparting a lateral outward movement on the second support member (103). The lateral outward movement imparted by the block (105) aids the support member (103) to firmly hold the second longitudinal surface (111) of the tube (101). Also, the first support member (102) is driven by a second external power source which provides necessary force to firmly hold the tube (101) between the first and the second support member (102 and 103). The punch (104) is positioned above the block (105) and is configured to a third external power source [not shown]. The first external power source drives the block (105) in the longitudinal direction, wherein the block (105) as said above imparts lateral out ward force on the second support member (103). The longitudinal force of the punch (104) driven by the third external power source is imparted over the free ends of the tube (101). The force imparted by the punch (104) acts as compressive force on one or both the ends of the tube (101). The compressive force plastically deforms the either ends of the tube (101) into the portion of the die formed by the first and second support members (102 and 103). Further, the compressive force acting on the ends of the tube (101) deforms the tube (101) into the shape of the die formed by the support members (102 and 103). The die as said above is created by the chamfer provided on the extreme ends of the first and second support member (102 and 103).

The first support member (102) includes an outer tube holder (106) and an outer insert (107) as shown in FIG.3 [one half of outer tube holder assembly]. The outer tube holder (106) and the outer insert (107) are connected by at least one means, such as but not limiting to mechanical joining and thermal joining. The outer tube holder (106) is a hollow cylindrical component split into two equal halves. The outer tube holder (106) is of uniform cross section i.e., the inner and the outer diameter of the holder (106) is same throughout. The outer insert (107) is a hollow cylindrical part with varying cross section. The outer insert (107) is also split equally into two halves, each half of outer insert is connected to the individual half of the outer holder (106). The outer insert (107) may be designed to define a portion of the die to satisfy the thickening purpose of the tube (101). The outer insert (107) on the extreme ends are chamfered, the chamfered ends define a portion of the die for the plastic deformation of the ends of tube (101). The second support member (103) includes an inner tube holder (108) and inner insert (109) as shown in FIG.2. The inner tube holder (108) is hollow cylindrical component, the cross section varies uniformly from the top to bottom. The uniformly varying cross section may be configured to house the block (105). The inner insert (109) may be designed to define a portion of a die to satisfy the thickening purpose of the tube (101). The inner insert (109) is chamfered at the one or both extreme ends, this chamfered portion defines a portion of the die for the plastic deformation of the ends of the tube (101). The inner insert (109) is also split equally into two halves, each half of inner insert (109) is connected to the individual half of the inner holder (108). Further, both the halves of the two components i.e., the inner tube holder assembly (108 and 109) and the outer tube holder assembly (106 and 107) is assembled together in the apparatus (100). The assembled components i.e., the outer tube holder assembly (106 and 107) and inner tube holder assembly (108and 109) form the first and the second support member (102 and 103) respectively. The chamfered ends of the first support member (102) and second support member (103) defines the complete die portion for plastic deformation of the ends of the tube.

Further, the tube (101) is held firmly over the central portion of the first and second longitudinal surfaces (110 and 111). The ends of the tube (101) other than the central portion of the longitudinal surface (110 and 111) are not supported. The ends of the tube (101) on one or both ends may be subjected to compressive force by a punch. The force imparted over the ends of the tube (101) plastically deforms the tube into the shape of the die created by the portions of the first and the second support members (102 and 103). The first support member (102) along with the second support member (103) together hold the tube firmly, supporting only the central portion of the first and second longitudinal surface (110 and 111). The force required to grip the portion of the tube (101) is imparted by the first and second external power source on the first and second support member (102 and 103) respectively. The first power source provides a longitudinal motion to the block (105), that moves into the inner tube holder (108). The block imparts a lateral outward force on the second support member (103), which in turn firmly holds the tube (101) along with support of first support member (102). The first support member (102) is driven by the second external power source for example a hydraulic actuator. Once the tube (101) is held firmly by the first and second support member (102 and 103), the tube is subjected to compressive force. The compressive force is imparted by the punch (104) which may be driven by the third external power source. As shown in FIG.4, the tube (101) is subjected compressive force on one or both ends. The compressive force that is imparted on the ends of the tube (101) plastically deforms the ends of the tube (101). The plastically deformed tube (101) takes the shape of the die that is formed by the portions of first and second support member (102 and 103) as said above. The thickness of the ends of the tube (101) increases after the plastic deformation, as it takes the shape of the die. The first and second external power sources may be any one of but not limiting to a hydraulic drive, pneumatic drive, and the like. The first and second and third external power sources may be used to drive the block (105), the punch (104) and first support member (102). However, the second support member (103) is driven by the block (105), which imparts a lateral outward force on the same. The block (105) may be anyone of the shape such as but not limiting to a wedge shape. The tube (101) formed using the said apparatus (100) and the said process may have a body portion (200) and a brim portion (201).

As shown in FIG.4a and 4b, the tube (101) includes of the body portion (200) and the brim portion (201). The body portion (200) of the tube (101) may be of uniform cross section. The brim portion (201) may be on one or both ends of the body portion (200) of the tube (101). The brim portion (201) is formed by the plastic deformation into the die. The brim (201) has a thickness greater than thickness of the body portion (201) of tube (101). The thickness of the brim portion (201) of the tube is about 20% to 30% greater than the thickness of the body portion (200) according to present disclosure is uniformly varying . As shown in FIG.4b, it picturizes a completely manufactured tube (101) held between first and second support member (102 and 103) of the apparatus (100). The ends of the tube (101) after deformation takes the shape of the die portion thereby increasing thickness only on the ends. The thickened ends of the tube (101) defines the brim portion (201) as shown in FIG.4b. The body portion (200) of the tube (101) is of uniform cross section. The process of thickening may be carried out on variety of materials such as but not limiting to a mild steel with certain alloy elements.

The apparatus (100) can simultaneous thicken the tube (101) on one or both the ends, this ensures lower cycle time which improves the productivity of the apparatus (100). The process has low operation cost over the conventional device due use of less tonnage equipment. Also, the tubes (101) undergo strain hardening during the process, facilitating in increase in strength of the tube (101).

Equivalents

With respect to the use of substantially any plural and/or singular terms herein, those having skill in the art can translate from the plural to the singular and/or from the singular to the plural as is appropriate to the context and/or application. The various singular/plural permutations may be expressly set forth herein for sake of clarity.

It will be understood by those within the art that, in general, terms used herein, are generally intended as "open" terms (e.g., the term "including" should be interpreted as "including but not limited to," the term "having" should be interpreted as "having at least," the term "includes" should be interpreted as "includes but is not limited to," etc.). It will be further understood by those within the art that if a specific number of an introduced claim recitation is intended, such an intent will be explicitly recited in the claim, and in the absence of such recitation no such intent is present. For example, as an aid to understanding the description may contain usage of the introductory phrases "at least one" and "one or more" to introduce claim recitations. However, the use of such phrases should not be construed to imply that the introduction of a claim recitation by the indefinite articles "a" or "an" limits any particular claim containing such introduced claim recitation to inventions containing only one such recitation, even when the same claim includes the introductory phrases "one or more" or "at least one" and indefinite articles such as "a" or "an" (e.g., "a" and/or "an" should typically be interpreted to mean "at least one" or "one or more"); the same holds true for the use of definite articles used to introduce claim recitations. In addition, even if a specific number of an introduced claim recitation is explicitly recited, those skilled in the art will recognize that such recitation should typically be interpreted to mean at least the recited number (e.g., the bare recitation of "two recitations," without other modifiers, typically means at least two recitations, or two or more recitations). Furthermore, in those instances where a convention analogous to "at least one of A, B, and C, etc." is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., "a system having at least one of A, B, and C" would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). In those instances where a convention analogous to "at least one of A, B, or C, etc." is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., "a system having at least one of A, B, or C" would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). It will be further understood by those within the art that virtually any disjunctive word and/or phrase presenting two or more alternative terms, whether in the description, or drawings, should be understood to contemplate the possibilities of including one of the terms, either of the terms, or both terms. For example, the phrase "A or B" will be understood to include the possibilities of "A" or "B" or "A and B."

While various aspects and embodiments have been disclosed herein, other aspects and embodiments will be apparent to those skilled in the art. The various aspects and embodiments disclosed herein are for purposes of illustration and are not intended to be limiting, with the true scope and spirit being indicated in the description.

Referral Numerals:

Description Reference Number
Apparatus 100
Tube 101
First support member 102
Second support member 103
Punch 104
Block 105
Outer tube holder 106
Outer insert 107
Inner tube holder 108
Inner insert 109
First longitudinal surface 110
Second longitudinal surface 111
Body portion 200
Brim portion 201

We claim:

1. An apparatus (100) for thickening a tube (101) at its brim (201), the apparatus (100) comprising:
a first support member (102), configured to rigidly support a first longitudinal surface (110) of the tube (101) along its length excluding one or both ends of the tube (101);
a second support member (103), configured to rigidly support a second longitudinal surface of the tube (101) along its length excluding the one or both ends of the tube (101); and
a punch (104) driven by an external power source, wherein the punch (104) is configured to exert force on either ends of the tube (101),
wherein, application of force by the punch (104) plastically deforms the ends of the tube (101) thickening the tube (101) at one or both ends.

2. The apparatus (100) as claimed in claim 1 comprises a block (105) driven by a first external power source, wherein a longitudinal force on the block (105) is configured to impart lateral outward movement on the second support member (103), to further support the second longitudinal surface (111) of the tube (101).

3. The apparatus (100) as claimed in claim 2, wherein the block (105) is wedge-shaped.

4. The apparatus (100) as claimed in claim 1, wherein the first support member (102) is driven by second an external power source.

5. The apparatus (100) as claimed in claim 1, wherein the first support member (102) includes an outer tube holder (106) and an outer insert (107).

6. The apparatus (100) as claimed in claim 5, wherein the outer tube holder (106) and the outer insert (107) are joined through at least one of mechanical joining and thermal joining.

7. The apparatus (100) as claimed in claim 6, wherein ends of the outer insert (107) are chamfered, such that the ends define a portion of die for plastic deformation of the ends of the tube (101).

8. The apparatus (100) as claimed in claim 1, wherein the second support member (103) includes an inner tube holder (108) and an inner insert (109).

9. The apparatus (100) as claimed in claim 8, wherein the inner tube holder (108) and the inner insert (109) are joined through at least one of mechanical joining and thermal joining.

10. The apparatus (100) as claimed in claim 9, wherein ends of the inner insert (109) are chamfered, such that the ends define a portion of die for plastic deformation of the ends of the tube (101).

11. The apparatus (100) as claimed in claim 1, wherein shape of the inner tube holder (108) corresponds to shape of the block.

12. The apparatus (100) as claimed in claim 1, wherein the external power source is a hydraulic drive.

13. The apparatus (100) as claimed in claim 1, wherein the first support member (102) and the second support member (103) are chamfered apart at the extreme ends on either ends of the support member, to be in non-contact with the tube’s brim (201).

14. The apparatus (100) as claimed in claim 1, wherein the first longitudinal surface (110) of the tube (101) is outer surface of the tube (101).

15. The apparatus (100) as claimed in claim 1, wherein the second longitudinal surface (111) of the tube is inner surface of the tube.

16. A tube (101) formed using an apparatus as claimed in claim 1.

17. A tube (101) comprising:
a body portion (200); and
a brim portion (201) at one or both ends of the body portion (200),
wherein, the brim portion (201) at one or both ends of the body portion (200) is such that, thickness of the brim portion (201) of the tube (101) is greater than thickness of the body portion (200) of the tube (101).

18. The tube (101) as claimed in claim 14, wherein the body portion (200) of the tube (101) is of uniform thickness.

19. The tube (101) as claimed in claim 15, wherein the thickness of the brim portion (201) of the tube (101) is about 20% - 30% greater than the thickness of the body portion (200) of the tube (101) .

20. A process of thickening a tube (101) at its brim (201), the process comprising:
supporting, by a first support member (102), a first longitudinal surface (110) of the tube (101) along its length excluding one or both ends of the tube (101);
supporting, by a second support member (103), a second longitudinal surface (111) of the tube along its length excluding one or both ends of the tube (101); and
compressing, by a punch (104), one or both ends of the tube (101),
wherein, application of force by the punch (104) plastically deforms the ends of the tube (101) increasing thickness of the tube (101) at one or both ends.

21. The process as claimed in claim 17 comprises moving by a block (105), the second support member (103) laterally outwards to support the central portion of the inner surface of the tube (101) rigidly.

22. The process as claimed in claim 18, wherein the block (105) is wedge-shaped.

23. The process as claimed in claim 19, wherein first support member (102), the punch (104) and the block (105) is driven by an external hydraulic power source.