CA2502564A1 - Assembly for cutting a tube - Google Patents
Assembly for cutting a tube Download PDFInfo
- Publication number
- CA2502564A1 CA2502564A1 CA002502564A CA2502564A CA2502564A1 CA 2502564 A1 CA2502564 A1 CA 2502564A1 CA 002502564 A CA002502564 A CA 002502564A CA 2502564 A CA2502564 A CA 2502564A CA 2502564 A1 CA2502564 A1 CA 2502564A1
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- CA
- Canada
- Prior art keywords
- cutting
- tube
- peripheral
- assembly
- cutting wheel
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
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Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21C—MANUFACTURE OF METAL SHEETS, WIRE, RODS, TUBES OR PROFILES, OTHERWISE THAN BY ROLLING; AUXILIARY OPERATIONS USED IN CONNECTION WITH METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL
- B21C37/00—Manufacture of metal sheets, bars, wire, tubes or like semi-manufactured products, not otherwise provided for; Manufacture of tubes of special shape
- B21C37/06—Manufacture of metal sheets, bars, wire, tubes or like semi-manufactured products, not otherwise provided for; Manufacture of tubes of special shape of tubes or metal hoses; Combined procedures for making tubes, e.g. for making multi-wall tubes
- B21C37/12—Making tubes or metal hoses with helically arranged seams
- B21C37/127—Tube treating or manipulating combined with or specially adapted for use in connection with tube making machines, e.g. drawing-off devices, cutting-off
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23D—PLANING; SLOTTING; SHEARING; BROACHING; SAWING; FILING; SCRAPING; LIKE OPERATIONS FOR WORKING METAL BY REMOVING MATERIAL, NOT OTHERWISE PROVIDED FOR
- B23D21/00—Machines or devices for shearing or cutting tubes
- B23D21/14—Machines or devices for shearing or cutting tubes cutting inside the tube
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B26—HAND CUTTING TOOLS; CUTTING; SEVERING
- B26D—CUTTING; DETAILS COMMON TO MACHINES FOR PERFORATING, PUNCHING, CUTTING-OUT, STAMPING-OUT OR SEVERING
- B26D3/00—Cutting work characterised by the nature of the cut made; Apparatus therefor
- B26D3/16—Cutting rods or tubes transversely
- B26D3/163—Cutting tubes from the inside
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- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Life Sciences & Earth Sciences (AREA)
- Forests & Forestry (AREA)
- Turning (AREA)
- Sawing (AREA)
- Knives (AREA)
Abstract
A tube cutting assembly has a pair of opposite, rotatable cutting wheels (6, 18), the outer of which is movable into engagement with a rotatable tube (3) for cutting through the tube wall (5). Each cutting wheel (6, 18) is provide d with a peripheral elastic ring (10, 22) which is configured to engage the tu be wall (5) and which is compressible towards the opposite cutting wheel. As a result, undesirable deformations of the cut tube end are avoided.
Description
ASSEMBLY FOR CUTTING A TUBE
Technical Field The present invention relates to an assembly for cutting a rotatable tube, in particular a helically-wound lock-seam tube to be used in ventilation ductworks.
Such tube cutting assemblies are often included in machines for producing helically-wound lock-seam tubes.
In these machines, a metal strip is helically wound into a tube in a forming head and locked in a helical lock seam. Basic examples of such machines or tube formers are shown in GB-A-2,213,748 (Fig. 1) and US-A-4,706,481 (Fig.
15). The tube cutting assembly is mounted after the form-ing head.
Background Art Known tube cutting assemblies of this type, often referred to as slitters by people skilled in the art, normally comprise a pair of opposite rotatable cutting wheels which are brought into engagement with the tube wall and co-operate to cut or sever the rotating tube.
A first cutting wheel is disposed inside the tube and a second cutting wheel is disposed outside the tube. When the tube is to be cut, the outer cutting wheel is brought into engagement with the outer surface of the tube and its cutting edge cuts through the tube wall against the cutting edge of the inner cutting wheel. An example of such a tube cutting assembly is disclosed in US-A-5,636,541 and its counterpart EP-A-749,787 which is here-by incorporated by reference (see in particular Figs 13 and 14 ) .
Under normal circumstances these known tube cutting assemblies work very well, but in certain cutting opera-tions the end of the cut tube is deformed in an undesir-able manner. This is illustrated in Fig. 1 which shows a cut tube seen from the end. Such undesirable deformations of the tube wall a-t the end sometimes occur on thin-walled tubes when the two cutting wheels are brought into CONFIRMATION COPY
Technical Field The present invention relates to an assembly for cutting a rotatable tube, in particular a helically-wound lock-seam tube to be used in ventilation ductworks.
Such tube cutting assemblies are often included in machines for producing helically-wound lock-seam tubes.
In these machines, a metal strip is helically wound into a tube in a forming head and locked in a helical lock seam. Basic examples of such machines or tube formers are shown in GB-A-2,213,748 (Fig. 1) and US-A-4,706,481 (Fig.
15). The tube cutting assembly is mounted after the form-ing head.
Background Art Known tube cutting assemblies of this type, often referred to as slitters by people skilled in the art, normally comprise a pair of opposite rotatable cutting wheels which are brought into engagement with the tube wall and co-operate to cut or sever the rotating tube.
A first cutting wheel is disposed inside the tube and a second cutting wheel is disposed outside the tube. When the tube is to be cut, the outer cutting wheel is brought into engagement with the outer surface of the tube and its cutting edge cuts through the tube wall against the cutting edge of the inner cutting wheel. An example of such a tube cutting assembly is disclosed in US-A-5,636,541 and its counterpart EP-A-749,787 which is here-by incorporated by reference (see in particular Figs 13 and 14 ) .
Under normal circumstances these known tube cutting assemblies work very well, but in certain cutting opera-tions the end of the cut tube is deformed in an undesir-able manner. This is illustrated in Fig. 1 which shows a cut tube seen from the end. Such undesirable deformations of the tube wall a-t the end sometimes occur on thin-walled tubes when the two cutting wheels are brought into CONFIRMATION COPY
engagement with the tube wall at high speed. The same difficulties may arise when the rotational speeds of the tube and the cutting wheels are not synchronised. The problem is particularly~common when cutting helically-wound lock-seam tubes, since the helical lock seam causes "bumps" at the cutting location between the cutting wheels which in turn may lead to deformations of the end of the cut tube.
The deformations at the end of the cut tube make it hard to connect various tubular components to the tube which are inserted in the tube from the end. Vdhen mount-ing ventilation duct systems including helically-wound lock-seam tubes of sheet metal, fittings like bends, T
pieces, reducers and other coupling members are connected to the ventilation ducts. If these fittings do not fit the ducts, the fitter either has to eliminate the end deformations manually or, if it comes to the worst, dis-card the duct as scrap.
Summary of the Invention The object of the invention is to provide a new tube cutting assembly which is improved over prior art and by means of which the problems above are eliminated or at least reduced.
This object is achieved by a tube cutting assembly having the features as defined in claim 1, preferred embodiments being defined in the dependent claims.
Owing to the peripheral elastic member provided on at least one of the cutting wheels of the tube cutting assembly, the cutting operation is very smooth~and no deformation occurs at the cut end of the tube. Vdhen the movable cutting wheel is brought into engagement with the tube at the cutting location, the peripheral elastic member is compressed and effectively damps the impact on the tube wall. Thus, the deforming forces that are exert-ed on the end of the tube being cut are reduced in compa-rison with prior-art tube cutters.
The deformations at the end of the cut tube make it hard to connect various tubular components to the tube which are inserted in the tube from the end. Vdhen mount-ing ventilation duct systems including helically-wound lock-seam tubes of sheet metal, fittings like bends, T
pieces, reducers and other coupling members are connected to the ventilation ducts. If these fittings do not fit the ducts, the fitter either has to eliminate the end deformations manually or, if it comes to the worst, dis-card the duct as scrap.
Summary of the Invention The object of the invention is to provide a new tube cutting assembly which is improved over prior art and by means of which the problems above are eliminated or at least reduced.
This object is achieved by a tube cutting assembly having the features as defined in claim 1, preferred embodiments being defined in the dependent claims.
Owing to the peripheral elastic member provided on at least one of the cutting wheels of the tube cutting assembly, the cutting operation is very smooth~and no deformation occurs at the cut end of the tube. Vdhen the movable cutting wheel is brought into engagement with the tube at the cutting location, the peripheral elastic member is compressed and effectively damps the impact on the tube wall. Thus, the deforming forces that are exert-ed on the end of the tube being cut are reduced in compa-rison with prior-art tube cutters.
In a preferred embodiment, both cutting wheels have a peripheral elastic member for engagement with the tube wall at the cutting location. This embodiment provides for a symmetric cutting operation with a damping effect on both sides of the tube wall. The deforming forces are reduced on both sides.
Preferably, the peripheral elastic members are off-set radially inside the cutting edge of the associated cutting wheel. As a result, the peripheral surface of each elastic member is supported by an opposite tube supporting surface of the opposite cutting wheel. This leads to a very smooth cutting operation that reduces the risk of deformations at the end of the cut tube.
Most preferably, each peripheral elastic member comprises an annular element which is fastened to the front surface of the associated cutting wheel. This design of the elastic members is advantageous since it is simple and provides a good damping effect.
In a preferred embodiment, the annular elastic ele-ment is clamped against the front surface of the asso-ciated cutting wheel by means of a clamping disc which is fastened to said front surface. This fastening technique is simple and has the specific advantage that it makes it easy to upgrade existing tube formers with an improved tube cutting assembly. Preferably, the clamping disc is fastened to said front surface by means of a central tightening screw which is coaxial with the rotational axis of the associated cutting wheel. This fastening of the annular elastic element is very secure and easy to handle.
In another aspect of the invention, the peripheral elastic member is mounted in a peripheral recess of the associated cutting wheel. By this design, a well-balanced damping effect is accomplished during the cutting opera-tion. Peripheral surfaces of the cutting wheel on either side of the peripheral elastic member can support the tube wall at the cutting location, which makes cutting smooth.
In a preferred embodiment, the peripheral elastic member is an annular element with a peripheral surface which is disposed radially outside the cutting edge of the associated cutting wheel. This design provides for an initial damping of the cutting impact, which reduces the risk of deformations at the end of the cut tube. Most preferably, the annular elastic element of this embodi-ment is clamped in the peripheral recess by means of a clamping disc.
It is preferred that the peripheral elastic member be made of a polymer material.
Brief Description of the Drawings The invention and its advantages will be further described in the following, reference being had to the accompanying diagrammic drawings which by way of example illustrate presently preferred embodiments.
Fig. 1 is an end view of a tube cut with a prior-art tube cutter, the tube wall having undesirable deforma-tions.
Fig. 2 is a sectional view of a tube cutting assem-bly according to a first aspect of the invention.
Fig. 3 is a sectional view of a tube cutting assem-bly according to a second aspect of the invention.
Detailed Description of Preferred Embodiments Fig. 1 shows a prior-art tube 1 of circular cross-section having undesirable deformations 2 at the cut end.
The deformations 2 are shown as indentations inwards, but the prior-art cutting operation can also cause other types of deformations, such as small cuts or burrs.
Fig. 2 shows a tube cutting assembly according to a first aspect of the invention. A tube in the shape of a helically-wound lock-seam tube 3 of sheet metal, produced in a tube former of the type discussed by way of intro-duction, is to be cut or severed by the tube cutting assembly. The tube 3 has a helical lock seam 4 which is shown schematically. The lock seam 4 projects outwards from the tube wall 5 which for instance has a wall thick-ness of 0.4-0.5 mm.
In a manner known per se, the tube 3 is rotated 5 about a centre axis C and moved in the direction of arrow A from a forming head (not shown).
The tube cutting assembly comprises a first cutting wheel 6 which is located inside the tube 3 and which is rotatable about an axis of rotation R1 parallel with the centre axis C of the tube 3. The inner cutting wheel 6 is circular and has a peripheral cutting edge 7 and a peri-pheral tube supporting surface 8 to be engaged with the tube wall 5. On the front surface 9 of the inner cutting wheel 6 there is mounted a peripheral elastic member, here in the shape of an annular element or ring 10, pre-ferably of polymer material. The elastic ring 10 is mounted by means of a circular clamping disc 11 which is fastened to the front surface 9 of the wheel 6 by means of a central tightening screw 12 which is coaxial with the rotational axis R1 of the wheel 6.
The components providing for the rotation of the inner cutting wheel 6 are known per se and will not be described in detail. For the sake of completeness, though, it should be mentioned that these components comprise a shaft 13 held by a nut 14 and journalled in bearings 15 included in a housing 16 and spaced by a spacer 17.
The tube cutting assembly further comprises an oppo-site second cutting wheel 18 which is located outside the tube 3 and which is rotatable about an axis of rotation R2 parallel with the centre axis C of the tube 3. The outer cutting wheel 18 is circular and of the same design as the inner cutting wheel 6. Thus, the outer wheel 18 has a peripheral cutting edge 19, a peripheral tube sup-porting surface 20 and a front surface 21. An elastic ring 22, preferably of polymer material, is mounted on the front surface 21 by means of a circular clamping disc 23 fastened by a tightening screw 24 which is coaxial with the rotational axis Rz of the outer wheel 18.
The components providing for the rotation of the outer wheel 18 are the same as for the inner wheel 6 and need not to be described in detail.
The outer cutting wheel 18 is movable in a direction perpendicular to the centre axis C of the tube 3 for bringing the opposite cutting wheels 6 and 18 into cut-ting engagement at a cutting location L between the wheels 6, 18. Means 25 which provide this movement (arrow B) are of known type and are only shown schematically.
The operation of the tube cutting assembly accord-ing to this first aspect of the invention will now be described.
The tube 3 is rotated and moved in the direction of arrow A. When the tube 3 is to be cut or severed, the lower or outer cutting wheel 18, which is rotating, is raised and brought into engagement with the outer surface of the tube wall 5. The cutting edge 19 of the outer wheel 18 cuts through the tube wall 5 and, in doing this, the tube supporting surface 20 of the outer wheel 18 abuts the outer surface of the tube wall 5. During this cutting movement, the inner cutting wheel 6 (which is rotating but stationary with respect to the cutting direction B) supports and backs up the outer wheel 18.
The cutting edge 7 of the inner cutting wheel 6 cuts through the tube wall 5 from the inside and the tube supporting surface 8 abuts the inner surface of the tube wall 5.
As the cutting operation proceeds, the respective cutting edges 7 and 19 as well as the respective tube supporting surfaces 8 and 20 abut the respective elastic rings 10 and 22 which are compressed. Owing to the com-pression of the elastic rings 10 and 22, the cutting of the tube 3 is very smooth and no "bumps" occur. The elas-tic rings 10 and 22 take up the transverse cutting forces and provide for a secure cutting of the tube 3 which is not deformed at the cut end.
Thus, the tube wall 5 is pressed between the peri-pheral surface l0a of the elastic ring 10 of the inner wheel 6 and the peripheral tube supporting surface 20 of the outer wheel 18. At the same time, the tube wall 5 is pressed between the peripheral surface 22a of the elastic ring 22 of the outer wheel 18 and~the peripheral tube supporting surface 8 of the inner wheel 6.
Not even the lock seam 4 causes any difficulties when it passes the cutting location L, since the elastic rings 10 and 22 effectively compensate for the projecting lock seam 4. Consequently, the former problems with lock seams in prior-art tube cutters are eliminated. The lock seam 4 does not cause any "bump" between the cutting wheels 6, 18.
The elastic rings 10 and 22 are both offset radial-ly inside the cutting edges 7 and 19 of the associated wheels 6 and 18. In other words, the peripheral surfaces l0a and 22a are disposed at a distance inwardly from the cutting edges 7 and 19. As a result, the cutting edges 7 and 19 can initiate the cutting through of the tube wall 5 before the elastic rings 10 and 22 are compressed in order to avoid undesirable deformations of the cut end of the tube 3. This leads to a very smooth cutting ope-ration and a tube end of perfect circular cross-section.
Fig. 3 shows a tube assembly according to a second aspect of the invention. The basic idea behind this structure is the same as described above, but the design of the cutting wheels is somewhat different.
The outer cutting wheel 30 has a peripheral elastic member, here in the shape of an annular ring 31, prefer-ably of polymer material, mounted in a peripheral recess 32 of the wheel 30. The elastic ring 31 is fastened in the recess 32 by means of a clamping disc 33 tightened by a screw 34 which is coaxial with the axis of rotation R2 of the outer wheel 30. The peripheral surface 31a of the elastic ring 31 is disposed radially outside the peripheral cutting edge 35 of the outer wheel 30, which means that the elastic ring 31 is first brought into engagement with the tube wall 5 in the cutting operation.
Thus, the compression of the elastic ring 31 starts.
The inner cutting wheel 36 has no elastic member, but two peripheral cutting edges 37 and 38, between which there is a peripheral tube supporting surface 39. In ope-ration, the outer wheel 30 is raised by means 25 (arrow B) and brought into engagement with the tube wall 5 at the cutting location L. The cutting edges 35, 37 and 38 co-operate to cut the tube 3, the elastic ring 31 being compressed by the tube supporting surface 39. It should be pointed out that the peripheral edge 40 of the clamp-ing disc 33 close to the elastic ring 31 acts as a cut-ting edge during this compression. The tube 3 is cut at two points, leaving a "ring" of the tube 3 as scrap.
The peripheral surfaces 30a and 33a of the outer cutting wheel 30 and the clamping disc 33 serve as tube supporting or back-up surfaces for the tube wall 5, which enhances the cutting operation.
The components providing the rotation of the two wheels 30 and 36 are the same as in the first structure and need not be described in detail.
An advantage of the tube cutting assembly according to the invention is that it can either be supplied as an attachment to an existing tube former or be mounted on a new tube former.
Finally, it should be emphasised that the invention is by no means restricted to the embodiments described above, and modifications are feasible within the scope of the inventive concept as expressed in the appended claims. Either one of or both of the opposite cutting wheels may be provided with a peripheral elastic member to be compressed during the cutting operation. Further-more, either one of or both of the cutting wheels can be movable in a direction transversely of the centre axis of the tube, although it is preferred for the outer wheel to be movable.
Preferably, the peripheral elastic members are off-set radially inside the cutting edge of the associated cutting wheel. As a result, the peripheral surface of each elastic member is supported by an opposite tube supporting surface of the opposite cutting wheel. This leads to a very smooth cutting operation that reduces the risk of deformations at the end of the cut tube.
Most preferably, each peripheral elastic member comprises an annular element which is fastened to the front surface of the associated cutting wheel. This design of the elastic members is advantageous since it is simple and provides a good damping effect.
In a preferred embodiment, the annular elastic ele-ment is clamped against the front surface of the asso-ciated cutting wheel by means of a clamping disc which is fastened to said front surface. This fastening technique is simple and has the specific advantage that it makes it easy to upgrade existing tube formers with an improved tube cutting assembly. Preferably, the clamping disc is fastened to said front surface by means of a central tightening screw which is coaxial with the rotational axis of the associated cutting wheel. This fastening of the annular elastic element is very secure and easy to handle.
In another aspect of the invention, the peripheral elastic member is mounted in a peripheral recess of the associated cutting wheel. By this design, a well-balanced damping effect is accomplished during the cutting opera-tion. Peripheral surfaces of the cutting wheel on either side of the peripheral elastic member can support the tube wall at the cutting location, which makes cutting smooth.
In a preferred embodiment, the peripheral elastic member is an annular element with a peripheral surface which is disposed radially outside the cutting edge of the associated cutting wheel. This design provides for an initial damping of the cutting impact, which reduces the risk of deformations at the end of the cut tube. Most preferably, the annular elastic element of this embodi-ment is clamped in the peripheral recess by means of a clamping disc.
It is preferred that the peripheral elastic member be made of a polymer material.
Brief Description of the Drawings The invention and its advantages will be further described in the following, reference being had to the accompanying diagrammic drawings which by way of example illustrate presently preferred embodiments.
Fig. 1 is an end view of a tube cut with a prior-art tube cutter, the tube wall having undesirable deforma-tions.
Fig. 2 is a sectional view of a tube cutting assem-bly according to a first aspect of the invention.
Fig. 3 is a sectional view of a tube cutting assem-bly according to a second aspect of the invention.
Detailed Description of Preferred Embodiments Fig. 1 shows a prior-art tube 1 of circular cross-section having undesirable deformations 2 at the cut end.
The deformations 2 are shown as indentations inwards, but the prior-art cutting operation can also cause other types of deformations, such as small cuts or burrs.
Fig. 2 shows a tube cutting assembly according to a first aspect of the invention. A tube in the shape of a helically-wound lock-seam tube 3 of sheet metal, produced in a tube former of the type discussed by way of intro-duction, is to be cut or severed by the tube cutting assembly. The tube 3 has a helical lock seam 4 which is shown schematically. The lock seam 4 projects outwards from the tube wall 5 which for instance has a wall thick-ness of 0.4-0.5 mm.
In a manner known per se, the tube 3 is rotated 5 about a centre axis C and moved in the direction of arrow A from a forming head (not shown).
The tube cutting assembly comprises a first cutting wheel 6 which is located inside the tube 3 and which is rotatable about an axis of rotation R1 parallel with the centre axis C of the tube 3. The inner cutting wheel 6 is circular and has a peripheral cutting edge 7 and a peri-pheral tube supporting surface 8 to be engaged with the tube wall 5. On the front surface 9 of the inner cutting wheel 6 there is mounted a peripheral elastic member, here in the shape of an annular element or ring 10, pre-ferably of polymer material. The elastic ring 10 is mounted by means of a circular clamping disc 11 which is fastened to the front surface 9 of the wheel 6 by means of a central tightening screw 12 which is coaxial with the rotational axis R1 of the wheel 6.
The components providing for the rotation of the inner cutting wheel 6 are known per se and will not be described in detail. For the sake of completeness, though, it should be mentioned that these components comprise a shaft 13 held by a nut 14 and journalled in bearings 15 included in a housing 16 and spaced by a spacer 17.
The tube cutting assembly further comprises an oppo-site second cutting wheel 18 which is located outside the tube 3 and which is rotatable about an axis of rotation R2 parallel with the centre axis C of the tube 3. The outer cutting wheel 18 is circular and of the same design as the inner cutting wheel 6. Thus, the outer wheel 18 has a peripheral cutting edge 19, a peripheral tube sup-porting surface 20 and a front surface 21. An elastic ring 22, preferably of polymer material, is mounted on the front surface 21 by means of a circular clamping disc 23 fastened by a tightening screw 24 which is coaxial with the rotational axis Rz of the outer wheel 18.
The components providing for the rotation of the outer wheel 18 are the same as for the inner wheel 6 and need not to be described in detail.
The outer cutting wheel 18 is movable in a direction perpendicular to the centre axis C of the tube 3 for bringing the opposite cutting wheels 6 and 18 into cut-ting engagement at a cutting location L between the wheels 6, 18. Means 25 which provide this movement (arrow B) are of known type and are only shown schematically.
The operation of the tube cutting assembly accord-ing to this first aspect of the invention will now be described.
The tube 3 is rotated and moved in the direction of arrow A. When the tube 3 is to be cut or severed, the lower or outer cutting wheel 18, which is rotating, is raised and brought into engagement with the outer surface of the tube wall 5. The cutting edge 19 of the outer wheel 18 cuts through the tube wall 5 and, in doing this, the tube supporting surface 20 of the outer wheel 18 abuts the outer surface of the tube wall 5. During this cutting movement, the inner cutting wheel 6 (which is rotating but stationary with respect to the cutting direction B) supports and backs up the outer wheel 18.
The cutting edge 7 of the inner cutting wheel 6 cuts through the tube wall 5 from the inside and the tube supporting surface 8 abuts the inner surface of the tube wall 5.
As the cutting operation proceeds, the respective cutting edges 7 and 19 as well as the respective tube supporting surfaces 8 and 20 abut the respective elastic rings 10 and 22 which are compressed. Owing to the com-pression of the elastic rings 10 and 22, the cutting of the tube 3 is very smooth and no "bumps" occur. The elas-tic rings 10 and 22 take up the transverse cutting forces and provide for a secure cutting of the tube 3 which is not deformed at the cut end.
Thus, the tube wall 5 is pressed between the peri-pheral surface l0a of the elastic ring 10 of the inner wheel 6 and the peripheral tube supporting surface 20 of the outer wheel 18. At the same time, the tube wall 5 is pressed between the peripheral surface 22a of the elastic ring 22 of the outer wheel 18 and~the peripheral tube supporting surface 8 of the inner wheel 6.
Not even the lock seam 4 causes any difficulties when it passes the cutting location L, since the elastic rings 10 and 22 effectively compensate for the projecting lock seam 4. Consequently, the former problems with lock seams in prior-art tube cutters are eliminated. The lock seam 4 does not cause any "bump" between the cutting wheels 6, 18.
The elastic rings 10 and 22 are both offset radial-ly inside the cutting edges 7 and 19 of the associated wheels 6 and 18. In other words, the peripheral surfaces l0a and 22a are disposed at a distance inwardly from the cutting edges 7 and 19. As a result, the cutting edges 7 and 19 can initiate the cutting through of the tube wall 5 before the elastic rings 10 and 22 are compressed in order to avoid undesirable deformations of the cut end of the tube 3. This leads to a very smooth cutting ope-ration and a tube end of perfect circular cross-section.
Fig. 3 shows a tube assembly according to a second aspect of the invention. The basic idea behind this structure is the same as described above, but the design of the cutting wheels is somewhat different.
The outer cutting wheel 30 has a peripheral elastic member, here in the shape of an annular ring 31, prefer-ably of polymer material, mounted in a peripheral recess 32 of the wheel 30. The elastic ring 31 is fastened in the recess 32 by means of a clamping disc 33 tightened by a screw 34 which is coaxial with the axis of rotation R2 of the outer wheel 30. The peripheral surface 31a of the elastic ring 31 is disposed radially outside the peripheral cutting edge 35 of the outer wheel 30, which means that the elastic ring 31 is first brought into engagement with the tube wall 5 in the cutting operation.
Thus, the compression of the elastic ring 31 starts.
The inner cutting wheel 36 has no elastic member, but two peripheral cutting edges 37 and 38, between which there is a peripheral tube supporting surface 39. In ope-ration, the outer wheel 30 is raised by means 25 (arrow B) and brought into engagement with the tube wall 5 at the cutting location L. The cutting edges 35, 37 and 38 co-operate to cut the tube 3, the elastic ring 31 being compressed by the tube supporting surface 39. It should be pointed out that the peripheral edge 40 of the clamp-ing disc 33 close to the elastic ring 31 acts as a cut-ting edge during this compression. The tube 3 is cut at two points, leaving a "ring" of the tube 3 as scrap.
The peripheral surfaces 30a and 33a of the outer cutting wheel 30 and the clamping disc 33 serve as tube supporting or back-up surfaces for the tube wall 5, which enhances the cutting operation.
The components providing the rotation of the two wheels 30 and 36 are the same as in the first structure and need not be described in detail.
An advantage of the tube cutting assembly according to the invention is that it can either be supplied as an attachment to an existing tube former or be mounted on a new tube former.
Finally, it should be emphasised that the invention is by no means restricted to the embodiments described above, and modifications are feasible within the scope of the inventive concept as expressed in the appended claims. Either one of or both of the opposite cutting wheels may be provided with a peripheral elastic member to be compressed during the cutting operation. Further-more, either one of or both of the cutting wheels can be movable in a direction transversely of the centre axis of the tube, although it is preferred for the outer wheel to be movable.
Claims (11)
1. An assembly for cutting a tube (3) which is rotatable about a centre axis (C) and which has a tube wall (5), comprising:
a first cutting wheel (6; 36) located inside the tube and rotatable about an axis of rotation (R1) paral-lel with the centre axis of the tube, the first cutting wheel (6; 36) having a peripheral cutting edge (7; 37) and a peripheral tube supporting surface (8; 39) to be engaged with the tube wall (5);
a second cutting wheel (18; 30) located outside the tube and opposite the first cutting wheel (6; 36), and rotatable about an axis of rotation (R2) parallel with the centre axis of the tube, the second cutting wheel (18; 30) having a peripheral cutting edge (19; 35) and a peripheral tube supporting surface (20; 30a) to be engaged with the tube wall (5); and means (25) for bringing the cutting wheels (6, 18;
30, 36) into cutting engagement with the tube wall (5) in a cutting direction (B) perpendicular to the centre axis of the tube for cutting through the tube wall (5) at a cutting location (L);
characterised in that at least one of the cutting wheels (6, 18; 30) has a peripheral elastic member (10, 22; 31) which is configured to be engaged with the tube wall (5) at the cutting location (L) and which is compressible towards the tube supporting surface (8, 20; 39) of the opposite cutting wheel.
a first cutting wheel (6; 36) located inside the tube and rotatable about an axis of rotation (R1) paral-lel with the centre axis of the tube, the first cutting wheel (6; 36) having a peripheral cutting edge (7; 37) and a peripheral tube supporting surface (8; 39) to be engaged with the tube wall (5);
a second cutting wheel (18; 30) located outside the tube and opposite the first cutting wheel (6; 36), and rotatable about an axis of rotation (R2) parallel with the centre axis of the tube, the second cutting wheel (18; 30) having a peripheral cutting edge (19; 35) and a peripheral tube supporting surface (20; 30a) to be engaged with the tube wall (5); and means (25) for bringing the cutting wheels (6, 18;
30, 36) into cutting engagement with the tube wall (5) in a cutting direction (B) perpendicular to the centre axis of the tube for cutting through the tube wall (5) at a cutting location (L);
characterised in that at least one of the cutting wheels (6, 18; 30) has a peripheral elastic member (10, 22; 31) which is configured to be engaged with the tube wall (5) at the cutting location (L) and which is compressible towards the tube supporting surface (8, 20; 39) of the opposite cutting wheel.
2. An assembly as claimed in claim 1, wherein each one of the cutting wheels (6, 18) has a peripheral elas-tic member (10, 22) which is disposed at the front sur-face (9, 21) of the cutting wheel (6, 18) and which has a peripheral surface (10a, 22a) configured to be engaged with the tube wall (5).
3. An assembly as claimed in claim 2, wherein each peripheral elastic member (10, 22) is offset radially inside the cutting edge (7, 19) of the associated cutting wheel (6, 18).
4. An assembly as claimed in any one of the preced-ing claims, wherein said at least one peripheral elastic member comprises an annular elastic element (10, 22) that is fastened to the front surface (9, 21) of the associat-ed cutting wheel (6, 18).
5. An assembly as claimed in claim 4, wherein the annular elastic element (10, 22) is clamped against the front surface (9, 21) of the associated cutting wheel (6, 18) by means of a clamping disc (11, 23) which is fastened to said front surface.
6. An assembly as claimed in claim 5, wherein the clamping disc (11, 23) is fastened to said front surface (9, 21) by means of a central tightening screw (12, 24) which is coaxial with the rotational axis (R1, R2) of the associated cutting wheel (6, 18).
7. An assembly as claimed in claim 1, wherein said at least one peripheral elastic member (31) is mounted in a peripheral recess (32) of the associated cutting wheel (30).
8. An assembly as claimed in claim 7, wherein said at least one peripheral elastic member is an annular elastic element (31) with a peripheral surface (31a) which is disposed radially outside with respect to the cutting edge (35) of the associated cutting wheel (30).
9. An assembly as claimed in claim 7 or 8, wherein said at least one peripheral elastic member (31) is clamped in the peripheral recess (32) by means of a clamping disc (33).
10. An assembly as claimed in any one of the preced-ing claims, wherein said at least one peripheral elastic member (10, 22; 31) is made of polymer material.
11. A machine for producing tubes, c h a r a c -t e r i s e d in that it has a tube cutting assembly as claimed in any one of claims 1-10.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| SE0203103A SE526005C2 (en) | 2002-10-18 | 2002-10-18 | Device for cutting pipes, and machine including such device |
| SE0203103-7 | 2002-10-18 | ||
| PCT/EP2003/011461 WO2004035239A2 (en) | 2002-10-18 | 2003-10-16 | Assembly for cutting a tube |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2502564A1 true CA2502564A1 (en) | 2004-04-29 |
Family
ID=20289320
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002502564A Abandoned CA2502564A1 (en) | 2002-10-18 | 2003-10-16 | Assembly for cutting a tube |
Country Status (8)
| Country | Link |
|---|---|
| EP (1) | EP1565280A2 (en) |
| JP (1) | JP2006502872A (en) |
| CN (1) | CN1705526A (en) |
| AU (1) | AU2003276114A1 (en) |
| CA (1) | CA2502564A1 (en) |
| RU (1) | RU2005114497A (en) |
| SE (1) | SE526005C2 (en) |
| WO (1) | WO2004035239A2 (en) |
Families Citing this family (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| ITFI20050258A1 (en) * | 2005-12-23 | 2007-06-24 | Perini Fabio Spa | MACHINE FOR THE PRODUCTION OF TUBES THROUGH STRIPES OF BULKY MATERIALS |
| JP4892327B2 (en) * | 2006-11-29 | 2012-03-07 | 株式会社富士機械工作所 | Tube cutting apparatus and tube cutting method |
| JP4264908B2 (en) | 2007-07-20 | 2009-05-20 | 株式会社富士機械工作所 | Tube cutting apparatus and tube manufacturing method |
| US9573205B2 (en) * | 2012-02-28 | 2017-02-21 | Cvtec Co., Ltd. | Rotary cutting apparatus and rotary cutting method |
| CN102825332B (en) * | 2012-09-07 | 2015-05-20 | 北京金鹏振兴铜业有限公司 | Auxiliary mechanism on disk slitting machine |
| CN104440983A (en) * | 2014-11-28 | 2015-03-25 | 桐乡市美达制鞋厂 | Automatic cutting device for corrugated hose |
| CN104741685B (en) * | 2015-04-10 | 2017-03-08 | 苏州斯莱克精密设备股份有限公司 | A kind of tank mouth trimming device for metal can |
| CN113263339B (en) * | 2021-05-11 | 2022-10-18 | 陕西国宏鼎泰能源服务有限公司 | A kind of bidirectional cutting machine for natural gas pipeline processing and natural gas pipeline processing technology |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US1753827A (en) * | 1926-12-01 | 1930-04-08 | Firm L Schuler A G Werkzeugmas | Tube-cutting machine |
| DE2538115A1 (en) * | 1975-08-27 | 1977-03-10 | Herbert Ing Grad Zimmermann | Helical seam welded pipe milling vibration damper - is conical roller with variable mass, linked to pipe support roller array |
| DE3707405A1 (en) * | 1986-05-24 | 1987-11-26 | Demgen Karl Willi | DEVICE FOR THE CHIP-FREE CUTTING OF TUBES |
| US5020351A (en) * | 1990-05-24 | 1991-06-04 | Spiro America Inc. | Apparatus for flattening irregular circumferential surfaces in spirally formed pipe |
| DE4332008C2 (en) * | 1993-09-21 | 1997-10-16 | Ero Edelstahl Rohrtechnik Gmbh | Cutting device for thin-walled pipes |
-
2002
- 2002-10-18 SE SE0203103A patent/SE526005C2/en not_active IP Right Cessation
-
2003
- 2003-10-16 JP JP2004544254A patent/JP2006502872A/en not_active Withdrawn
- 2003-10-16 AU AU2003276114A patent/AU2003276114A1/en not_active Abandoned
- 2003-10-16 CA CA002502564A patent/CA2502564A1/en not_active Abandoned
- 2003-10-16 RU RU2005114497/02A patent/RU2005114497A/en not_active Application Discontinuation
- 2003-10-16 WO PCT/EP2003/011461 patent/WO2004035239A2/en not_active Application Discontinuation
- 2003-10-16 CN CNA2003801015729A patent/CN1705526A/en active Pending
- 2003-10-16 EP EP03808729A patent/EP1565280A2/en not_active Withdrawn
Also Published As
| Publication number | Publication date |
|---|---|
| EP1565280A2 (en) | 2005-08-24 |
| AU2003276114A1 (en) | 2004-05-04 |
| SE526005C2 (en) | 2005-06-14 |
| SE0203103D0 (en) | 2002-10-18 |
| WO2004035239A3 (en) | 2004-07-01 |
| JP2006502872A (en) | 2006-01-26 |
| SE0203103L (en) | 2004-04-19 |
| AU2003276114A8 (en) | 2004-05-04 |
| CN1705526A (en) | 2005-12-07 |
| WO2004035239A2 (en) | 2004-04-29 |
| RU2005114497A (en) | 2006-02-10 |
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| Date | Code | Title | Description |
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| FZDE | Dead |