CA2038538A1 - Mold block liner in travelling mold tunnel - Google Patents
Mold block liner in travelling mold tunnelInfo
- Publication number
- CA2038538A1 CA2038538A1 CA 2038538 CA2038538A CA2038538A1 CA 2038538 A1 CA2038538 A1 CA 2038538A1 CA 2038538 CA2038538 CA 2038538 CA 2038538 A CA2038538 A CA 2038538A CA 2038538 A1 CA2038538 A1 CA 2038538A1
- Authority
- CA
- Canada
- Prior art keywords
- mold
- liner
- grooves
- ribs
- mold block
- 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
Links
Landscapes
- Moulds For Moulding Plastics Or The Like (AREA)
- Extrusion Moulding Of Plastics Or The Like (AREA)
Abstract
ABSTRACT
A mold block for use in a travelling mold tunnel for molding profiled plastics material tube is provided with a removable, interchangable liner to modify the profile of produced tube. The liners are useful for modifying the outer diameter of annularly ribbed tube or the rib profile and height of the annularly ribbed tube. If the liners are used for molding corrugated tube, the inner diameter may also be modified according to the thickness of the liner. The liners may be separate rib liners and band liners or may be one piece liners shaped according to the required tube profile. They may be attached to the molds by screws or may lodge in seating grooves of the mold.
A mold block for use in a travelling mold tunnel for molding profiled plastics material tube is provided with a removable, interchangable liner to modify the profile of produced tube. The liners are useful for modifying the outer diameter of annularly ribbed tube or the rib profile and height of the annularly ribbed tube. If the liners are used for molding corrugated tube, the inner diameter may also be modified according to the thickness of the liner. The liners may be separate rib liners and band liners or may be one piece liners shaped according to the required tube profile. They may be attached to the molds by screws or may lodge in seating grooves of the mold.
Description
This invention relates to travelling mold tunnels for the molding of rigid and semi-rigid plastics material profiled tube. The tube may be, for example, corrugated or ribbed tube. The invention also relates to mold blocks for use in such travelling mold tunnels and to liners for such mold blocks.
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Mold blocks utilizable in travelling mold tunnels are often located in two endless loops of mold blocks which bring co-operating pairs of mold blocks together on forward runs of each loop to form the mold tunnel.
However single loops of mold blocks which are closed to form a tunnel on one run and open on a related run are also possible. Inner surfaces of the mold blocks are machined or otherwise provided with mold surfaces to form the tube.
In practice, a parison of molded thermoplastics material is introduced to the mold tunnel to be molded against the mold surface. The formed tube cools and sets as the tunnel moves along the forward runs of the loops of mold blocks. When the tube is formed and self supporting, the mold blocks move away towards a return run thus ending the tunnel and releasing the tube. The inner surface of the tube may be formed by an inner forming plug which is usually a cooling plug. Whien the tube is corrugated tube, the single or outer corrugated tube may be forced against a corrugated mold and any inner wall may be formed on this plug .
It is not necessary that the mold blocks be brought together to form the tunnel by means of the : '~' ':
~03853~3 endless loops of mold blocks. Other means of forming the tunnel are possible as, for e~ample, described in PCT
Patent Application No. Ca 90/00372 to the same inventor.
The mold blocks themselve~ are bulky and expensive in both materials and in the labour necessary in machining their mold faces. Each set of mold blocks may be utilized for only one specific profile of tube even if the general diameter of the tube is similar.
This problem is well recognized and attempts have been made to reduce the very high investment necessary for providing the various sets of mold blocks for a corresponding variety of tube profiles. One such attempt has involved the provision of a set of mold block carriers which may be used with different sets of mold blocks.
This solution has somewhat alleviated the problem since the mold blocks themselves may be of relatively simple construction as regards their external fittings.
It is, however, up to this time necessary to have a separate set of sturdy mold blocks for each tube profile.
Not only is the expense of such sets of mold blocks appreciable but their maintenance is also considerable. In operation, the movements of the mold blocks and their opening and closing to form the mold tunnel subjects them to considerable general wear and to breakage.
Breakage is especially prone at points in travel o the mold blocks where they may knock against other eguipment such as the die, the cooling plug or even each other~ As the mold blocks turn into their forward runs to form the tunnel they are prone to hîtting each other or .. . - . : , - . . . ..
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' .' , ' ' ''. ' ' . ~' 203853~3 other apparatus parts. Repair or replacement of worn or broken mold blocks is costly.
The problem is possibly emphasized in the production of ribbed tube. The process for the production of such tube is much more akin to injection molding than the blow molding technique which may be used in the production of corrugated tube and is, therefore, subject to the greater pressures and equipment stresses which are present in injection molding.
The above-mentioned problems have now been addressed by the present inventor, who has addressed the specific problem of providing a mold block which is capable of adaptation for forming different tube profiles.
-:
According to the invention there is provided a travelling mold tunnel for continuously molding profiled tube surface, e.g. an annularly or helically ribbed outer surface or corrugated tube, and comprising mold blocks having interchangable mold liners acting together to form ;
the mold tunnel, each mold block comprising a mold block base and a removable mold liner, the mold block base having an inner surface forming a seat for the mold liner; ~ -and the mold liner being removably seated through an outer surface conforming in shape to the seat of the mold block base, and having an inner surface configured to form at least part of a mold surface for tube. The travelling mold tunnel may be of the type in which the mold blocks are arranged in one or two endlesæ loops coming together to form a tunnel in a forward run of each loop. It may, however, be of other types.
' :' The present invention may be useful in the production of ribbed tube having circumferentially - 4 - 203~53~
extending upstanding ribs spaced generally smooth surface bands. "Generally smooth surface" is intended to mean generally smooth in comparison with the upstanding ribs.
Thus a generally smooth surface may be a surface which includes various surface m~rkings such as annular or helical ridges or grooves, the height or depth of which is not great as compared with that of the upstanding ribs.
Each mold block base may be provided with mold grooves configured to mold the ribs and each mold block liner may have a mold surface configured to mold at least one of the bands, the mold block liner being seated on a respective mold block and located to mold said one of the bands. The liner may be removably atached to the mold block so that it may be replaceable by a different liner, e.g. one having a different thickness to produce tube of different diameter.
Alternatively or additionally, each mold block base may be provided with mold grooves configured to mold rib side walls but having a depth greater than necessary for molding the tips of ribs of a desired height, and each mold block liner may comprise a rib tip forming an insert for the rib forming grooves. The inserts may be replaceable by different inserts for molding ribs of grater or lesser height or of different profile to mold ribs of different profile.
It is possible to provide a single mold block liner which seats in seating grooves of the mold block base. The seating grooves generally correspond to desired locations for the provision of ribs in resulting molded tubes. The liner has surfaces configured to mold the bands and has mold grooves extending into each seating groove configured to mold a rib.
203~3538 It may be possible by way of mold block linPrs to provide tube of varying diameter and varying rib height or profile. Thus, if one rib tip forming liner is used in one groove of a mold block a rib tip forming liner of greater or lesser depth may be used in another groove to produce a different height of rib. Similarly, different band diameters may be obtained by different band liners.
If the tube to be molded is corrugated tube, through the use of suitably profiled liners, it is possible to change the inner or outer diameter of the tube. Thus mold block liners may rest in the inner corrugations of a mold block to define the depth of the resulting corrugation.
The liner may be formed ~rom various materials -such as stainless steel, steel, aluminum, brass, bronze, etc.
, ~:
The invention includes the lined mold blocks and the liners themselves.
Embodiments of the invention will now be described by way of e~ample with reference to the drawings, in which:
Figure 1 is a longitudinal cross-section of a mold block for the production of ribbed tube in a travelling mold tunnel and having liners according to ~;
the present invention; and Figure 2 is a similar section of another mold block for ribbed tube having another embodiment of a liner according to the invention;
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Figure 3 is a longitudinal cross-section of mold blocks in a travelling mold tunnel for molding corrugated tube, having liners according to the present invention.
Referring first to Figure 1, mold block 10 are part of a travelling mold tunnel 12. Each mold block 10 is configured for molding ribbed tube 14 having ribs 16 and bands 18 between the ribs 16.
Each mold block 10 comprises a mold block bsse 22 and rmovable, interchangable, band liners 24 and rib tip liners 26. It will be appreciated that the band ljners 24 may be used without the rib tip liners 28 or vice versa.
The mold block base 22 corresponds roughly in shape to a conventional mold block but it will have sufficient diameter to accomodate band liners 24a, 24b of different thickness. Grooves 30 wh;ch in a conventional mold block would be configured to exactly mold tube ribs 16, are deeper than would be necessary for that purpose.
The increased depth is to act as a seating for rib tip liners 26a, 28b which, as shown, line the grooves 30 at the e~treme tip and have different depths according to the height of the required ribs. The rib tip liners 26 may have walls merging into the tip to partially, or even wholly, line the depth of the grooves 30.
As illustrated, a single mold block base 22 is provided along its length with band liners 24a, 24b of different thicknesses and rib tip liners 26a, 28b of different depths. While such longitudinal variation is possible, it is more likely that for any one tube, the bands and ribs will be of constant thickness and height.
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Fixing means may be separately provided for each rib tip liner 26a, 26b but, within the depth of groove 30, provision of specific attachment might be labour intensive and provide problems in roughness at the rib tip. It is :
considered that a friction fit of rib tip liner 26 into groove 30 is normally satisfactory.
. .
If it is desired to provide a tube with the same general diameter but with a different configuration of rib, the rib tip liners may be replaced by a set of liners having the configuration to mold the desired rib shape~
Except for tube of very different diameter, it may not be necessary to utilize a completely different set of mold blocks 11 - only the liners need be changed.
:.
Somewhat similar considerations apply to the band liners 24. Band liners 24 may be provided in different thicknesses so that some adjustment of tube diameter without the use of different mold bases 22 is possible.
The diameter of tube may be adjusted by band liners 24.
Band liners 22 seat against those portions of the mold base 22 between rib forming grooves 30. However, unless further grooves and complementary tongues are provided in the respective mold bases 22 and outer surfaces of band liners 24, a friction fit of the band liners 24 is not as suitable as for the rib tip liners 26. Conveniently, band liners 24 are attached to the mold bases 22 by screws 32.
When both rib tip liners 26 and band liners 24 are used, these may be integrally connected by a thin skin lining the walls of rib forming groove 30.
It is, quite possible that liners for paired mold blocks which cooperate one with the other to enclose a tube section may vary in thickness or depth. Thus, if it : . . ' . . ' ' ~ - 8 - ~03~3~
is desired to form tube which will bend more easily in one direc~ion, the rib height and/or band thickness may be adjusted circumferentially so that the tube is thinner or has shallower ribs on the side when greater flexion is required.
When worn or chipped or otherwise broken, the liners may be removed and replaced. They may also be replaced by different configurations.
Figure 2 shows a slightly different embodiment utilizing the concept of rib tip liners connected to or separate from band liners. Reference numbers which are also used in Figure 1 are used to denote similar parts.
As illustrated, the integrated liner 40 cover the whole of the mold base seating surface 41. The integration of the mold liners may be achieved by formina the liner in one piece or by flush surfaces 43 between rib lip liners and band liners. The mold base may be machined with seating grooves 42. These seating grooves 42 are not intended to carry out a molding function and need not be machined for this purpose. The ease of construction may be somewhat simplified iince the sealing grooves 42 ma~ be wider and not so steeply contoured as those required for molding ribs.
The integrated liner 40 has an outer surface complementary to the seating surface 41 of the mold base 22, and an inner æurface accurately machined to provide the required tube profile. The integrated liner 40 may have sufficient structure to be self-supporting and thickened walls 44 of the rib forming grooves 30 may provide strength advantage. While such an integrated liner 40 may be attachable to mold base 22 utilizing screws i2 similar to those shown in Figure 1, such attachment may not be necessary since it may be possible to achieve a secure snap fitting of liner 40 into mold base 22.
'~' - 9 - 203~3538 A possible advantage of the arrangement of the inventor, especially that of Figure 2, is that the mold bases may be made of less e~pensive material then has been possible for use as mold blocks in the past. The reason for this is that the whole of the mold surface is provided in liner 40 and thus it is only liner 40 which must be made of a material suitable for providing such a mold face.
Figures 3 illustrates a mold base 22 for producing corrugated tube. Where possible similar reference numerals have been used to denote similar parts. The mold bases 22 have liners 40a, 40b.
A further feature of the invention as applied to corrugated tube molding, is that the inner diameter of the tube may be varied in addition to the outer diameter.
Thus, the liners 40a, 40b which nest in the inwardly projecting corrugations of mold bases 10, define the inner diameter of corrugated tube 15. The liners 40a, 40b are deeper than liners 40a, and the mold base 22 is shown bro~en between liners 40a,40b in order to illustrate how tubes 41a and 41b of different diameters may be molded.
It is, of course, possible to use separate liners for altering only the mold troughs or ridges. Again screws 32 are illustrated to hold the mold liners 25 but a snap fit may also be possible. In the case of a snap fit, the corrugations of the mold blocks will hold the liners securely during their tunnel turn.
Again, it should be noted that the variations illustrated will not normally all be expected in a single tube but are capable of being implemented alone or in combination.
Other advantages and modifications will be apparent to a man skilled in the art and are regarded as within the scope of the appended claims.
.
.
... . : . :.. , . . , .~ :
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~.
Mold blocks utilizable in travelling mold tunnels are often located in two endless loops of mold blocks which bring co-operating pairs of mold blocks together on forward runs of each loop to form the mold tunnel.
However single loops of mold blocks which are closed to form a tunnel on one run and open on a related run are also possible. Inner surfaces of the mold blocks are machined or otherwise provided with mold surfaces to form the tube.
In practice, a parison of molded thermoplastics material is introduced to the mold tunnel to be molded against the mold surface. The formed tube cools and sets as the tunnel moves along the forward runs of the loops of mold blocks. When the tube is formed and self supporting, the mold blocks move away towards a return run thus ending the tunnel and releasing the tube. The inner surface of the tube may be formed by an inner forming plug which is usually a cooling plug. Whien the tube is corrugated tube, the single or outer corrugated tube may be forced against a corrugated mold and any inner wall may be formed on this plug .
It is not necessary that the mold blocks be brought together to form the tunnel by means of the : '~' ':
~03853~3 endless loops of mold blocks. Other means of forming the tunnel are possible as, for e~ample, described in PCT
Patent Application No. Ca 90/00372 to the same inventor.
The mold blocks themselve~ are bulky and expensive in both materials and in the labour necessary in machining their mold faces. Each set of mold blocks may be utilized for only one specific profile of tube even if the general diameter of the tube is similar.
This problem is well recognized and attempts have been made to reduce the very high investment necessary for providing the various sets of mold blocks for a corresponding variety of tube profiles. One such attempt has involved the provision of a set of mold block carriers which may be used with different sets of mold blocks.
This solution has somewhat alleviated the problem since the mold blocks themselves may be of relatively simple construction as regards their external fittings.
It is, however, up to this time necessary to have a separate set of sturdy mold blocks for each tube profile.
Not only is the expense of such sets of mold blocks appreciable but their maintenance is also considerable. In operation, the movements of the mold blocks and their opening and closing to form the mold tunnel subjects them to considerable general wear and to breakage.
Breakage is especially prone at points in travel o the mold blocks where they may knock against other eguipment such as the die, the cooling plug or even each other~ As the mold blocks turn into their forward runs to form the tunnel they are prone to hîtting each other or .. . - . : , - . . . ..
- - - . ~,:, - : . .
' ' , . :
~ .. . , . . ~ : .
: . , . . : :
: . :. . , . , :
' .' , ' ' ''. ' ' . ~' 203853~3 other apparatus parts. Repair or replacement of worn or broken mold blocks is costly.
The problem is possibly emphasized in the production of ribbed tube. The process for the production of such tube is much more akin to injection molding than the blow molding technique which may be used in the production of corrugated tube and is, therefore, subject to the greater pressures and equipment stresses which are present in injection molding.
The above-mentioned problems have now been addressed by the present inventor, who has addressed the specific problem of providing a mold block which is capable of adaptation for forming different tube profiles.
-:
According to the invention there is provided a travelling mold tunnel for continuously molding profiled tube surface, e.g. an annularly or helically ribbed outer surface or corrugated tube, and comprising mold blocks having interchangable mold liners acting together to form ;
the mold tunnel, each mold block comprising a mold block base and a removable mold liner, the mold block base having an inner surface forming a seat for the mold liner; ~ -and the mold liner being removably seated through an outer surface conforming in shape to the seat of the mold block base, and having an inner surface configured to form at least part of a mold surface for tube. The travelling mold tunnel may be of the type in which the mold blocks are arranged in one or two endlesæ loops coming together to form a tunnel in a forward run of each loop. It may, however, be of other types.
' :' The present invention may be useful in the production of ribbed tube having circumferentially - 4 - 203~53~
extending upstanding ribs spaced generally smooth surface bands. "Generally smooth surface" is intended to mean generally smooth in comparison with the upstanding ribs.
Thus a generally smooth surface may be a surface which includes various surface m~rkings such as annular or helical ridges or grooves, the height or depth of which is not great as compared with that of the upstanding ribs.
Each mold block base may be provided with mold grooves configured to mold the ribs and each mold block liner may have a mold surface configured to mold at least one of the bands, the mold block liner being seated on a respective mold block and located to mold said one of the bands. The liner may be removably atached to the mold block so that it may be replaceable by a different liner, e.g. one having a different thickness to produce tube of different diameter.
Alternatively or additionally, each mold block base may be provided with mold grooves configured to mold rib side walls but having a depth greater than necessary for molding the tips of ribs of a desired height, and each mold block liner may comprise a rib tip forming an insert for the rib forming grooves. The inserts may be replaceable by different inserts for molding ribs of grater or lesser height or of different profile to mold ribs of different profile.
It is possible to provide a single mold block liner which seats in seating grooves of the mold block base. The seating grooves generally correspond to desired locations for the provision of ribs in resulting molded tubes. The liner has surfaces configured to mold the bands and has mold grooves extending into each seating groove configured to mold a rib.
203~3538 It may be possible by way of mold block linPrs to provide tube of varying diameter and varying rib height or profile. Thus, if one rib tip forming liner is used in one groove of a mold block a rib tip forming liner of greater or lesser depth may be used in another groove to produce a different height of rib. Similarly, different band diameters may be obtained by different band liners.
If the tube to be molded is corrugated tube, through the use of suitably profiled liners, it is possible to change the inner or outer diameter of the tube. Thus mold block liners may rest in the inner corrugations of a mold block to define the depth of the resulting corrugation.
The liner may be formed ~rom various materials -such as stainless steel, steel, aluminum, brass, bronze, etc.
, ~:
The invention includes the lined mold blocks and the liners themselves.
Embodiments of the invention will now be described by way of e~ample with reference to the drawings, in which:
Figure 1 is a longitudinal cross-section of a mold block for the production of ribbed tube in a travelling mold tunnel and having liners according to ~;
the present invention; and Figure 2 is a similar section of another mold block for ribbed tube having another embodiment of a liner according to the invention;
i , . ~ , . . .
- . . - : - - . . :. : . ~
., . :, ;, : :- ~. , .
.~ , : . . .. :
,, ~ . . , : . ~ . :
- 6 - 2~3~
Figure 3 is a longitudinal cross-section of mold blocks in a travelling mold tunnel for molding corrugated tube, having liners according to the present invention.
Referring first to Figure 1, mold block 10 are part of a travelling mold tunnel 12. Each mold block 10 is configured for molding ribbed tube 14 having ribs 16 and bands 18 between the ribs 16.
Each mold block 10 comprises a mold block bsse 22 and rmovable, interchangable, band liners 24 and rib tip liners 26. It will be appreciated that the band ljners 24 may be used without the rib tip liners 28 or vice versa.
The mold block base 22 corresponds roughly in shape to a conventional mold block but it will have sufficient diameter to accomodate band liners 24a, 24b of different thickness. Grooves 30 wh;ch in a conventional mold block would be configured to exactly mold tube ribs 16, are deeper than would be necessary for that purpose.
The increased depth is to act as a seating for rib tip liners 26a, 28b which, as shown, line the grooves 30 at the e~treme tip and have different depths according to the height of the required ribs. The rib tip liners 26 may have walls merging into the tip to partially, or even wholly, line the depth of the grooves 30.
As illustrated, a single mold block base 22 is provided along its length with band liners 24a, 24b of different thicknesses and rib tip liners 26a, 28b of different depths. While such longitudinal variation is possible, it is more likely that for any one tube, the bands and ribs will be of constant thickness and height.
.. . : . ~- : . , . . .. : .
Fixing means may be separately provided for each rib tip liner 26a, 26b but, within the depth of groove 30, provision of specific attachment might be labour intensive and provide problems in roughness at the rib tip. It is :
considered that a friction fit of rib tip liner 26 into groove 30 is normally satisfactory.
. .
If it is desired to provide a tube with the same general diameter but with a different configuration of rib, the rib tip liners may be replaced by a set of liners having the configuration to mold the desired rib shape~
Except for tube of very different diameter, it may not be necessary to utilize a completely different set of mold blocks 11 - only the liners need be changed.
:.
Somewhat similar considerations apply to the band liners 24. Band liners 24 may be provided in different thicknesses so that some adjustment of tube diameter without the use of different mold bases 22 is possible.
The diameter of tube may be adjusted by band liners 24.
Band liners 22 seat against those portions of the mold base 22 between rib forming grooves 30. However, unless further grooves and complementary tongues are provided in the respective mold bases 22 and outer surfaces of band liners 24, a friction fit of the band liners 24 is not as suitable as for the rib tip liners 26. Conveniently, band liners 24 are attached to the mold bases 22 by screws 32.
When both rib tip liners 26 and band liners 24 are used, these may be integrally connected by a thin skin lining the walls of rib forming groove 30.
It is, quite possible that liners for paired mold blocks which cooperate one with the other to enclose a tube section may vary in thickness or depth. Thus, if it : . . ' . . ' ' ~ - 8 - ~03~3~
is desired to form tube which will bend more easily in one direc~ion, the rib height and/or band thickness may be adjusted circumferentially so that the tube is thinner or has shallower ribs on the side when greater flexion is required.
When worn or chipped or otherwise broken, the liners may be removed and replaced. They may also be replaced by different configurations.
Figure 2 shows a slightly different embodiment utilizing the concept of rib tip liners connected to or separate from band liners. Reference numbers which are also used in Figure 1 are used to denote similar parts.
As illustrated, the integrated liner 40 cover the whole of the mold base seating surface 41. The integration of the mold liners may be achieved by formina the liner in one piece or by flush surfaces 43 between rib lip liners and band liners. The mold base may be machined with seating grooves 42. These seating grooves 42 are not intended to carry out a molding function and need not be machined for this purpose. The ease of construction may be somewhat simplified iince the sealing grooves 42 ma~ be wider and not so steeply contoured as those required for molding ribs.
The integrated liner 40 has an outer surface complementary to the seating surface 41 of the mold base 22, and an inner æurface accurately machined to provide the required tube profile. The integrated liner 40 may have sufficient structure to be self-supporting and thickened walls 44 of the rib forming grooves 30 may provide strength advantage. While such an integrated liner 40 may be attachable to mold base 22 utilizing screws i2 similar to those shown in Figure 1, such attachment may not be necessary since it may be possible to achieve a secure snap fitting of liner 40 into mold base 22.
'~' - 9 - 203~3538 A possible advantage of the arrangement of the inventor, especially that of Figure 2, is that the mold bases may be made of less e~pensive material then has been possible for use as mold blocks in the past. The reason for this is that the whole of the mold surface is provided in liner 40 and thus it is only liner 40 which must be made of a material suitable for providing such a mold face.
Figures 3 illustrates a mold base 22 for producing corrugated tube. Where possible similar reference numerals have been used to denote similar parts. The mold bases 22 have liners 40a, 40b.
A further feature of the invention as applied to corrugated tube molding, is that the inner diameter of the tube may be varied in addition to the outer diameter.
Thus, the liners 40a, 40b which nest in the inwardly projecting corrugations of mold bases 10, define the inner diameter of corrugated tube 15. The liners 40a, 40b are deeper than liners 40a, and the mold base 22 is shown bro~en between liners 40a,40b in order to illustrate how tubes 41a and 41b of different diameters may be molded.
It is, of course, possible to use separate liners for altering only the mold troughs or ridges. Again screws 32 are illustrated to hold the mold liners 25 but a snap fit may also be possible. In the case of a snap fit, the corrugations of the mold blocks will hold the liners securely during their tunnel turn.
Again, it should be noted that the variations illustrated will not normally all be expected in a single tube but are capable of being implemented alone or in combination.
Other advantages and modifications will be apparent to a man skilled in the art and are regarded as within the scope of the appended claims.
.
.
... . : . :.. , . . , .~ :
:. , - .. ,. . , .. ,- : .
Claims (19)
1. A travelling mold tunnel for continuously molding profiled tube and comprising mold blocks acting together to form the mold tunnel, each mold block comprising a mold block base and a removable mold liner, the mold block base having an inner surface forming a seat for the mold liner;
and the mold liner being removably seated through an outer surface conforming in shape to the seat of the mold block base, and having an inner surface configured to form at least part of a mold surface for tube.
and the mold liner being removably seated through an outer surface conforming in shape to the seat of the mold block base, and having an inner surface configured to form at least part of a mold surface for tube.
2. A travelling mold tunnel as claimed in claim 1 in which the mold blocks are arranged in one or two endless loops coming together in pairs on a forward run of each loop to form the mold tunnel.
3, A travelling mold tunnel as claimed in claim 1 for the production of ribbed tube having circumferentially extending upstanding ribs spaced by generally smooth surface bands, each mold block base being provided with mold grooves configured to mold the ribs and each mold block liner having a mold surface configured to mold at least one of the bands, the mold block liner being seated on a respective mold block base located to mold said one of the bands.
4. A travelling mold tunnel as claimed in claim 3 in which the grooves are configured to mold ribs are selected from annular and helical ribs.
5. A travelling mold tunnel as claimed in claim 1 for the production of ribbed tube having circumferentially extending upstanding ribs spaced by generally smooth surface bands, each mold block base being provided with mold grooves configured to mold rib side walls but having a depth greater than necessary for molding the tips of ribs of a desired height, the mold block liner comprising a rib tip forming insert for each of the rib forming grooves.
6. A travelling mold tunnel as claimed in claim 5 in which the grooves of the liner are configured to mold ribs selected from annular and helical ribs.
7. A travelling mold tunnel as claimed in claim 1 for the production of ribbed tube having circumferentially extending ribs spaced by generally smooth surface bands, the mold block bases being provided with seating grooves generally corresponding to desired locations for the provision of ribs in resulting tubes, a liner being seated in said seating grooves and having surfaces configured to mold said bands having a mold groove extending into each seating groove configured to mold a rib.
8. A travelling mold tunnel as claimed in claim 9 in which the mold grooves of the liner are configured to mold ribs selected from annular and helical ribs.
9. A travelling mold tunnel as claimed in claim 1 for the production of corrugated tube having circumferentially extending corrugations, each mold block base being corrugated to provide seating grooves having a depth greater than necessary for molding the tips of corrugations of a desired height, the mold block liner comprising an insert for the grooves.
10. A travelling mold tunnel as claimed in claim 9 in which liners are provided for outwardly directed ridges of the mold base which ridges alternate with the grooves.
11. A mold block for use in a travelling mold tunnel of mold blocks for continuously molding profiled tube;
each mold block comprising a mold block base and a mold liner, the mold block base having an inner surface forming a seat for the mold liner; and the mold liner being seated through an outer surface conforming in shape to the eat of the mold block base, and having an inner surface configured to form at least part of a mold surface for tube.
each mold block comprising a mold block base and a mold liner, the mold block base having an inner surface forming a seat for the mold liner; and the mold liner being seated through an outer surface conforming in shape to the eat of the mold block base, and having an inner surface configured to form at least part of a mold surface for tube.
12. A mold block as claimed in claim 11 for the production of ribbed tube having circumferentially extending upstanding ribs spaced by generally smooth surface bands, each mold block base being provided with mold grooves configured to mold the ribs and each mold block liner having mold surface configured to mold at least one of the bands, the mold block liner being seated on a respective mold block base located to mold said one of the bands band.
13. A mold block as claimed in claim 12 in which the grooves are configured to mold ribs are selected from annular and helical ribs.
14. A mold block as claimed in claim 11 for the production of ribbed tube having circumferentially extending upstanding ribs spaced by generally smooth surface bands, each mold block base being provided with mold grooves configured to mold rib side walls but having a depth greater than necessary for molding the tips of ribs of a desired height the mold block liner comprising a rib tip forming insert for each of the rib forming grooves.
15. A mold block as claimed in claim 14 in which the grooves are configured to mold ribs selected from annular and helical ribs.
16. A mold block as claimed in claim 11 for the production of ribbed tube having circumferentially extending ribs spaced by generally smooth surface bands, the mold block bases being provided with seating grooves generally corresponding to desired locations for the provision of ribs in resulting tubes, a liner being removably seated in said sealing grooves and having surfaces configured to mold said bands having a mold groove extending into each sealing groove configured to mold a rib.
17. A mold block as claimed in claim 16 in which the mold grooves of the liner are configured to mold ribs selected from annular and helical ribs.
18. A mold block travelling mold tunnel as claimed in claim 15 for use in the production of corrugated tube having circumferentially extending corrugations, each mold block base being corrugated to provide seating grooves having a depth greater than necessary for molding the tips of corrugations of a desired height, the mold block liner comprising an insert for the grooves.
19. A mold block as claimed in claim 18 in which liners are provided for outwardly directed ridges of the mold base which ridges alternate with the grooves.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA 2038538 CA2038538A1 (en) | 1991-03-18 | 1991-03-18 | Mold block liner in travelling mold tunnel |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA 2038538 CA2038538A1 (en) | 1991-03-18 | 1991-03-18 | Mold block liner in travelling mold tunnel |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2038538A1 true CA2038538A1 (en) | 1992-09-19 |
Family
ID=4147205
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 2038538 Abandoned CA2038538A1 (en) | 1991-03-18 | 1991-03-18 | Mold block liner in travelling mold tunnel |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA2038538A1 (en) |
-
1991
- 1991-03-18 CA CA 2038538 patent/CA2038538A1/en not_active Abandoned
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| FZDE | Dead |