CA2211897A1 - Expanding tool for cold forming - Google Patents
Expanding tool for cold formingInfo
- Publication number
- CA2211897A1 CA2211897A1 CA002211897A CA2211897A CA2211897A1 CA 2211897 A1 CA2211897 A1 CA 2211897A1 CA 002211897 A CA002211897 A CA 002211897A CA 2211897 A CA2211897 A CA 2211897A CA 2211897 A1 CA2211897 A1 CA 2211897A1
- Authority
- CA
- Canada
- Prior art keywords
- expanding
- members
- mandrel
- tool according
- ring
- 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
- 238000007789 sealing Methods 0.000 claims description 22
- 229920000098 polyolefin Polymers 0.000 claims description 8
- 239000000463 material Substances 0.000 claims description 7
- 238000005553 drilling Methods 0.000 abstract 2
- 230000008719 thickening Effects 0.000 abstract 1
- 239000012530 fluid Substances 0.000 description 6
- 230000004308 accommodation Effects 0.000 description 2
- 230000004323 axial length Effects 0.000 description 2
- 230000015572 biosynthetic process Effects 0.000 description 2
- 238000010276 construction Methods 0.000 description 2
- 230000037431 insertion Effects 0.000 description 2
- 238000003780 insertion Methods 0.000 description 2
- 206010010904 Convulsion Diseases 0.000 description 1
- JGFZNNIVVJXRND-UHFFFAOYSA-N N,N-Diisopropylethylamine (DIPEA) Chemical compound CCN(C(C)C)C(C)C JGFZNNIVVJXRND-UHFFFAOYSA-N 0.000 description 1
- 229910001315 Tool steel Inorganic materials 0.000 description 1
- 230000002411 adverse Effects 0.000 description 1
- 238000006073 displacement reaction Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 239000013013 elastic material Substances 0.000 description 1
- 238000003825 pressing Methods 0.000 description 1
- 230000002441 reversible effect Effects 0.000 description 1
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21D—WORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS OR PROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21D41/00—Application of procedures in order to alter the diameter of tube ends
- B21D41/02—Enlarging
- B21D41/026—Enlarging by means of mandrels
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Shaping Of Tube Ends By Bending Or Straightening (AREA)
- Earth Drilling (AREA)
- Treatment Of Fiber Materials (AREA)
Abstract
The expanding tool has a cylindrical expanding mandrel (5) consisting of a plurality of cylinder-sector expanding components (10) which are interchangeably secured and guided on a face of a housing (1). The expanding mandrel (5) has a partially conical inner drilling (6) with which engages an expanding cone (4) operating together with actuating means (2) which advance the expanding cone (4) into the inner drilling (6) of the expanding mandrel (5) to expand the end (19) of a pipe fitted on said mandrel (5). In addition, the expanding mandrel (5) is bevelled (9) at its free end. Between the bevel (9) and a thickening (11) from which the holding component proceeds there is at least one recess (18) running around the entire periphery of the expanding mandrel (5).
Description
-Expanding Tool for Cold Forming Technical Field The present invention relates to an expanding tool for temporary expansion of tube ends made of cross-linked polyolefin, consisting of a generally cylindrically shaped expanding mandrel which is provided with an at least partially conically shaped inner bore and which is subdivided in axial direction into a multiple number of expanding members substantially having the shape of a cylindrical sector, further consisting of respective holding members protruding from the outer circumference of the expanding members, biassing means acting upon the holding members for biassing the expanding members into mutual engagement in order to form the generally cylindrically shaped expanding mandrel, recesses extending along the circumference in the expanding members intermediate rounded free ends and the holding members, a housing within which the holding members are radially displaceably guided, conically shaped expanding means for engaging the at least partially conically shaped inner bore of the expanding mandrel, and actuating means for reversibly axially displacing the expanding means within the inner bore of the expanding mandrel and expanding the same against the force of the biassing means.
Background Art Such expanding tool is known from International Published Patent Application No. WO 9418486 and serves for reversibly expanding tube ends which are made of cross-linked polyolefin and provided with a clamping ring; after expansion, the tube ends are pushed onto a connector having a connecting member which is provided with an external Substitute Page IPEA/EP
.
flange. The tube end thus expanded at ambient temperature, after being pushed onto the connecting member, is subject to self-reconversion at ambient temperature resulting in a firm and sealing connection.
The expanding tool includes a generally cylindrically shaped expanding mandrel which is subdivided into a number of expanding members and defines a conically shaped inner bore into which a piston can be advanced which is mechanically, electrically or pressure fluid driven and has a correspondingly conically tapering end. The piston is arranged within a housing having an end wall at which the expanding members are located. Each expanding member has a rounded front end; a recess is formed in its circumference at a spacing from the front end. A radial member is located at the rear end of each expanding member and extends between housing covers which are screwed onto the front end of the housing and between which the expanding members are radially displaceably guided. In the inoperative condition, the expanding members are held together by means of an annular spring which acts upon the circumference of the radial members.
For reversibly expanding the tube end, the rounded end of the expanding members is first inserted into the tube end.
The expansion is, then, effected by advancing the piston into the conically shaped inner bore of the expanding mandrel and is defined by engagement surfaces at the expanding members. The expanding members are forced apart against the force of the annular spring. After the thus effected expansion, the piston is withdrawn and the expanding members are returned into their starting position under the action of the annular spring. During this expansion, the circumferential edges of the forced-apart Substitute Page IEPA/EP
expanding members engage the inner wall of the tube end to be expanded whereby notches arise in the inner wall of the tube and may result in leaks. In the region of the recesses of the expanding members, the inner wall of the tube does not contact the bottom of the recesses. The notches caused by the circumferential edges of the expanding members, therefore, are not formed in the region of the recesses.
The recesses are dimensioned such that their axial width exceeds the axial width of the external flange at the connecting member of the connector so that the connection to the connecting member is produced in a region which is free of the notches.
From U.S. Patent No. 3,385,087, there is known an expanding tool for expanding tube ends, for example, the ends of exhaust pipes. Such tool includes an expanding mandrel which is actuated by means of a double acting, pressure fluid operated piston. The expanding mandrel extends generally conically into expanding members which define a conically shaped inner bore in the inoperative condition. At their outer side, the expanding members have a circumferential groove into which an O-ring is inlaid which is made of, for example, rubber and serves to hold the expanding members in place. After pushing on the tube end, the expanding mandrel is actuated in order to force apart the expanding members and thereby expand the pushed-on tube end. After the expanding operation, the piston is withdrawn so that the expanding members can return into the inoperative position. The tube end is expanded due to plastic deformation and preserves its expanded dimension.
A further, similar expanding tool according to German Published Patent Application No. 42207g4 for expanding the tube ends of reversibly deformable plastic tubes includes Substitute Page IEPA/EP
-expanding members without recesses at their circumference.
An expanding tool according to European Published Patent Application No. 0619152 includes a clamping cap which is connected to the expanding members by means of specifically constructed connecting and guiding means.
Furthermore, there is known from German Published Patent Application No. 3817442 as well as German Utility Model No.
9404513 a connector comprising at least one connecting member for connection to a reversibly expanded tube end.
For firm and sealing connection to the tube end, the connecting member is provided with at least one holding element defining an outer surface which gradually slopes towards the free end of the holding member, and a surface which steeply slopes towards the opposite side. The gradually sloping outer surface facilitates pushing-on the expanded tube end while the steeply sloped surface conjointly with the gradually sloping outer surface defines a sealing edge which is of significance for forming a firm and sealing connection.
The initially mentioned expanding tool, due to the recesses at the outer circumference of the expanding members, does prevent the formation of notches in the inner wall of the tube end by means of the edges of the expanding members in the region of the recesses during expansion. A
sufficient depth of the recesses is therefore required.
However, due to the gaps formed between the forced-apart expanding members and the recesses, circumferential ribs arise at the inner wall and protrude into the interior of the expanded tube end to such extent as to significantly impede the pushing-on operation of the tube end after removal of the expanding mandrel.
Substitute Page IEPA/EP
-Disclosure of the Invention Accordingly, it is the object of the invention to provide an expanding tool of the initially mentioned type which ensures firm and sealing engagement of the expanded tube end to the particular connecting member and which does not adversely affect the connecting operation.
In accordance with the invention, this object is achieved in that a ring, which is made of a material having a self-reconversion behavior comparable to that of cross-linked polyolefin, is received in the recesses.
In the presence of the ring there is formed a uniformly deformed region at the inner wall of the expanded tube end in the area of the recesses and between the expanding members and this region protrudes less into the interior as in the case of the absence of the ring. The pushing-on operation of the tube end onto the connecting member is facilitated thereby. Additionally, the self-reconvertible ring has the advantage of contributing to better holding together the expanding members and providing for the expanding members an additional restoring force in addition to that of the annular spring after withdrawal of the expanding cone.
It is particularly advantageous using an expanding tool in conjunction with connectors having connecting members which comprise the aforementioned holding elements including a sealing edge and wherein the recesses and rings at the expanding members are aligned to this sealing edge.
Specifically, the recesses at the expanding members may be axially arranged in a manner such that the sealing edge at the holding element is disposed symmetrically relative to Substitute Page IEPA/EP
-5a the recesses. If desired, there may be provided more than one recess at the expanding mandrel and more than one sealing edge at the connecting member.
In such construction of the expanding mandrel, a tube end region, when compared to the absence of the ring, is less but uniformly expanded and extends in circumferentially closed manner around its inner wall. This region experiences a small expansion and self-reconversion which does not impede the pushing-on operation during passage over the sealing edge of the connecting member. It is thereby ensured that, notwithstanding the gaps which arise between the expanding members during the expanding operation, at least this region of the tube end comes to firmly and sealingly engage the connecting member on both sides of the sealing edge around its entire inner circumference whereby a firm and sealing connection is formed in toto.
Brief Description of the Drawings Exemplary embodiments of the inventive expanding tool are illustrated in the drawings and will be explained and described in detail hereinbelow having regard to the reference characters. There are shown in Figure 1 a longitudinal section through an exemplary embodiment of the expanding tool according to the invention;
Figure 2 a cross-section through the expanding tool as shown in Figure 1 along the line II-II;
Substitute Page IEPA/EP
5b -Figure 3 a longitudinal section through a detail of Figure l;
Figure 4 a longitudinal section through a modified 5construction of the expanding tool as shown in Figure 1; and Figure 5 a view of a connector for use in conjunction with the expanding tool as shown in Figure 1 or Figure 4.
Preferred Embodiments of the Invention Figure 1 shows a longitudinal section through a first exemplary embodiment of an expanding tool including a housing 1 which contains at one end thereof actuating means 2 for actuating the expanding tool. In the illustrated Substitute Page IEPA/EP
exemplary embodiment the actuating means 2 comprise a pressure fluid operated piston 3 which is connected to expanding means in the form of an expanding cone 4 by means of, for example, a screw connection. Instead of the pressure fluid operated piston 3 there may also be provided different actuating means like, for example, mechanical actuating means. The pressure fluid may be axially or radially fed to the housing 1. The housing 1 may be provided with holding means permitting the housing to be held during operation; the housing is constructed such as to also permit overhead work.
At the opposite end of the housing 1 there is arranged a generally cylindrically shaped expanding mandrel 5. This expanding mandrel 5 contains an inner bore 6 comprising a conically shaped bore portion 7, which is engaged or can be brought into engagement with the expanding mandrel 4, and a cylindrical bore portion 8 in the free end thereof. At this free end, the expanding mandrel 5 is provided with a chamfer 9 which may extend at an angle in the range of 5~
to 20~ relative to the circumferential surface of the expanding mandrel 5. The edges which delimit the chamfer 9, are rounded. The chamfer 9 as well as its rounded edges prevent damages to the inner wall of the a tube end 19 into which the expanding mandrel 5 is inserted for expansion.
The expanding mandrel 5 is multiply subdivided in lengthwise direction and comprises a number of expanding members 10 which assume the shape of cylinder sectors; in the illustrated exemplary embodiment, see Figure 2, the expanding mandrel 5 is subdivided eightfold and thus comprises eight expanding members 10. In the inoperative or non-actuated condition of the expanding mandrel 1, the expanding members 10 engage each other in circumferential direction and thus define a generally cylindrical circumferential surface.
A thickened section 11 is formed at the inner end of the expanding mandrel 5 or at the inner ends of the expanding members 10, respectively. Holding members extend therefrom and thereby the expanding mandrel 5 is exchangeably held in the associated end of the housing 1. In detail, each one of the holding members comprises an arm 12 which radially projects from the circumference of the thickened section 11 and which is provided at its circumference with an accommodation 13 for receiving biassing means such as, for example, an annular spring 14. The annular spring exerts a radially inwardly directed bias on the expanding members 10 whereby the expanding members 10 are held in mutual engagement in the non-actuated condition of the expanding mandrel 5 and whereby the generally cylindrical circumferential surface of the expanding mandrel 5 is formed. The radially projecting arms 12 are radially displaceably placed in guide means at the associated end wall of the housing 1 and such guide means comprise a holding plate 15 and a bearing plate 16 provided with a slide element 17. The holding plate 15 is releasably mounted at the end wall of the housing by means of screws so that the expanding members 10 or the expanding mandrel 5, respectively, are exchangeably arranged at the end wall of the housing 1 by means of the radial arms 12 and the holding plate 15.
Respective recesses 18 are located at the expanding members 10 intermediate the thickened section 11 and the chamfer 9 and constructed such as to form a circumferential groove in the closed or non-actuated state of the expanding mandrel 5. Preferably, the edges of the recesses 18 are Substitute Page IEPA/EP
bevelled in order to avoid damages to the tube end 19 upon insertion of the expanding mandrel 5.
The longitudinally sectional illustration of Figure 3 shows in detail the expanding mandrel 5 and a ring 28 which is inlaid into the recesses 18. This ring completely or partially fills the recesses 18. It is made of an elastic material or a material which is self-reconvertible at ambient temperature and which, if desired, may be reinforced. Preferably, it is made of a material having a self-reconversion behavior which is comparable to that of the expanded tube end and likewise may consist of cross-linked polyolefin.
In this as well as the exemplary embodiment described hereinbelow, the members such as the expanding cone and the expanding members of the expanding mandrel which are subjected to high mechanical stress, are manufactured from high-order tool steel. There is thus prevented, on the one hand, the formation of frictions and seizures between the parts which act upon each other, and deformation of the expanding members under the action of high expanding forces, on the other hand.
In the upper half of Figure 1 the expanding tool is shown in the inoperative condition. In this condition, the expanding mandrel 5 merely is placed within the conically shaped bore portion 7 of the inner bore 6 of the expanding mandrel 5 and there is no axially directed force which acts upon the expanding cone 4. The expanding members 10 are, then, in mutual engagement and the expanding mandrel 5 forms a generally cylindrical body as shown in Figure 2.
Substitute Page IEPA/EP
Upon applying pressure to the piston 3, this piston and therewith the expanding cone 4 are displaced within the housing 1 towards the expanding mandrel 5. The expanding cone 4 is thereby forced into the conically shaped bore portion 7 whereby the expanding members 10 are urged apart in radial direction against the force of the annular spring 14. The lower half of Figure 1 shows the expanding cone 4 in the terminal position of its displacement path in which position the maximum expansion of the expanding mandrel 5 is achieved. During this expansion, the gaps which arise between the expanding members 10, are bridged by the ring 28 which is received within the recesses 18 of the expanding members 10 and which is expanded conjointly therewith.
For expansion of a tube end, the expanding mandrel 5 is inserted, in the inoperative condition of the expanding tool, into a tube end 19 of a material which preferably is self-reconvertible at ambient temperature such as, for example, cross-linked polyolefin. During such insertion, the end wall of the tube end 19 engages the thickened section 11 and thereby the axial length of the to-be-expanded tube end 19 is delimited. Upon actuating the expanding cone 4, the expanding members 10 are outwardly urged against the force of the annular spring 14 whereby the tube end 19 is expanded by a corresponding amount.
During this operation, the inner surface of the tube end 19 engages the outer surface of the expanding mandrel 5, however, not entirely in the region of the ring 28, which is received in the recesses 18 and bridges the gaps between the forced-apart expanding members 10. In correspondence therewith, there is formed at the inner wall of the expanded tube end 19 a section or land which extends in circumferential direction, which protrudes inwardly and Substitute Page IEPA/EP
-which has a height determined by the depth of the recesses 18, the thickness of the ring 28 and the extension of the expanded ring 28 in the region between the expanding members 5.
The significance of the ring 28 and the land formed thereby at the inner wall of the expanded tube end 19 will be recognized in view of the connector to which the expanded tube end 19 is connected by means of its self-reconversion. Such connector may be constructed, forexample, like the tube connector according to German Utility Model No. G9404513 and is illustrated in longitudinal section in Figure 5. The tube connector 20 defines a straight piece of tubing comprising connecting members 21 at its opposite ends. Each one of the connecting members 21 includes a holding element 22 for connection to an expanded tube end like the tube end 19. Each one of the holding elements 22 includes an outer surface 23 which gradually slopes towards the free end of the tube connector 21 and a sealing edge 24 which steeply slopes on the other side.
The recesses 18 of the expanding members 10 are aligned to the axial position of the sealing edge 24 at the connecting member 21 onto which the expanded tube end 19 is placed. Preferably, the sealing edge 24 is symmetrically disposed relative to the recesses 18 such that the lands, which remain at the circumference of the inner wall at the tube end 19 after expansion, also extend symmetrically relative to the sealing edge 24 in axial direction. These lands protrude inwardly to an extent less than in the absence of the ring 28 and thereby facilitate the pushing-on operation of the expanded tube end 19 onto the connecting member 21 across the sealing edge 24. Otherwise, Substitute Page IEPA/EP
however, the lands are also subject to a likewise reversible deformation for a short period of time. As a consequence, these lands will engage, after self-reconversion, the connecting member 21 on both sides of the 5 sealing edge 24 around its entire circumference whereby a firm and sealing connection between the tube end 19 and the connecting member 21 is obtained at least in this region.
Additionally, the ring 28 represents part of the biassing means since the presence of the ring 28 has the effect of 10 holding together the expanding members 10 of the expanding mandrel 5 and subjecting the same to a further restoring force in addition to that of the annular spring 14 after withdrawal of the expanding cone 4.
The connecting member 21 of the tube connector 20, if desired, may comprise more than one sealing edge 24; in such case, there are present more than one recess 18 at corresponding locations of the expanding mandrel 5.
Figure 4 is an illustration which corresponds to Figure 1 and shows a modified construction of the expanding tool.
Identical parts therein are denoted by the same reference characters. There will be recognized therein the housing 1 containing the actuating means 2 in the form of a pressure fluid operated piston 3 which cooperates with an expanding cone 4.
An expanding mandrel 25 includes an inner bore 26 which is of conical configuration throughout and extends along the entire axial length of the expanding mandrel 25.
Otherwise, also here the expanding mandrel 25 is composed of eight expanding members which are held together under the bias of an annular spring 14. The annular spring 14 is held in an accommodation 13 of radial arms 12 which extend Substitute Page IEPA/EP
-lla from a thickened .section 11 at the inner end of the expanding mandrel 25 and which are radially displaceably arranged at the end wall of the housing 1 between a holding plate 15 and a bearing plate 16 having a slide element 17.
The rounded edge of the expanding mandrel 25 is connected by means of a chamfer 9 to the remaining part of the expanding mandrel 25; at least one recess 18 is located intermediate the chamfer 9 and the thickened section 11 of the expanding members 10 and a ring 28 (not shown) is inlaid thereinto in correspondence with the showing of Figure 3. The function and mode of operation of this expanding tool correspond to those which have been described hereinabove with reference to Figures 1 to 3.
Substitute Page IEPA/EP
Background Art Such expanding tool is known from International Published Patent Application No. WO 9418486 and serves for reversibly expanding tube ends which are made of cross-linked polyolefin and provided with a clamping ring; after expansion, the tube ends are pushed onto a connector having a connecting member which is provided with an external Substitute Page IPEA/EP
.
flange. The tube end thus expanded at ambient temperature, after being pushed onto the connecting member, is subject to self-reconversion at ambient temperature resulting in a firm and sealing connection.
The expanding tool includes a generally cylindrically shaped expanding mandrel which is subdivided into a number of expanding members and defines a conically shaped inner bore into which a piston can be advanced which is mechanically, electrically or pressure fluid driven and has a correspondingly conically tapering end. The piston is arranged within a housing having an end wall at which the expanding members are located. Each expanding member has a rounded front end; a recess is formed in its circumference at a spacing from the front end. A radial member is located at the rear end of each expanding member and extends between housing covers which are screwed onto the front end of the housing and between which the expanding members are radially displaceably guided. In the inoperative condition, the expanding members are held together by means of an annular spring which acts upon the circumference of the radial members.
For reversibly expanding the tube end, the rounded end of the expanding members is first inserted into the tube end.
The expansion is, then, effected by advancing the piston into the conically shaped inner bore of the expanding mandrel and is defined by engagement surfaces at the expanding members. The expanding members are forced apart against the force of the annular spring. After the thus effected expansion, the piston is withdrawn and the expanding members are returned into their starting position under the action of the annular spring. During this expansion, the circumferential edges of the forced-apart Substitute Page IEPA/EP
expanding members engage the inner wall of the tube end to be expanded whereby notches arise in the inner wall of the tube and may result in leaks. In the region of the recesses of the expanding members, the inner wall of the tube does not contact the bottom of the recesses. The notches caused by the circumferential edges of the expanding members, therefore, are not formed in the region of the recesses.
The recesses are dimensioned such that their axial width exceeds the axial width of the external flange at the connecting member of the connector so that the connection to the connecting member is produced in a region which is free of the notches.
From U.S. Patent No. 3,385,087, there is known an expanding tool for expanding tube ends, for example, the ends of exhaust pipes. Such tool includes an expanding mandrel which is actuated by means of a double acting, pressure fluid operated piston. The expanding mandrel extends generally conically into expanding members which define a conically shaped inner bore in the inoperative condition. At their outer side, the expanding members have a circumferential groove into which an O-ring is inlaid which is made of, for example, rubber and serves to hold the expanding members in place. After pushing on the tube end, the expanding mandrel is actuated in order to force apart the expanding members and thereby expand the pushed-on tube end. After the expanding operation, the piston is withdrawn so that the expanding members can return into the inoperative position. The tube end is expanded due to plastic deformation and preserves its expanded dimension.
A further, similar expanding tool according to German Published Patent Application No. 42207g4 for expanding the tube ends of reversibly deformable plastic tubes includes Substitute Page IEPA/EP
-expanding members without recesses at their circumference.
An expanding tool according to European Published Patent Application No. 0619152 includes a clamping cap which is connected to the expanding members by means of specifically constructed connecting and guiding means.
Furthermore, there is known from German Published Patent Application No. 3817442 as well as German Utility Model No.
9404513 a connector comprising at least one connecting member for connection to a reversibly expanded tube end.
For firm and sealing connection to the tube end, the connecting member is provided with at least one holding element defining an outer surface which gradually slopes towards the free end of the holding member, and a surface which steeply slopes towards the opposite side. The gradually sloping outer surface facilitates pushing-on the expanded tube end while the steeply sloped surface conjointly with the gradually sloping outer surface defines a sealing edge which is of significance for forming a firm and sealing connection.
The initially mentioned expanding tool, due to the recesses at the outer circumference of the expanding members, does prevent the formation of notches in the inner wall of the tube end by means of the edges of the expanding members in the region of the recesses during expansion. A
sufficient depth of the recesses is therefore required.
However, due to the gaps formed between the forced-apart expanding members and the recesses, circumferential ribs arise at the inner wall and protrude into the interior of the expanded tube end to such extent as to significantly impede the pushing-on operation of the tube end after removal of the expanding mandrel.
Substitute Page IEPA/EP
-Disclosure of the Invention Accordingly, it is the object of the invention to provide an expanding tool of the initially mentioned type which ensures firm and sealing engagement of the expanded tube end to the particular connecting member and which does not adversely affect the connecting operation.
In accordance with the invention, this object is achieved in that a ring, which is made of a material having a self-reconversion behavior comparable to that of cross-linked polyolefin, is received in the recesses.
In the presence of the ring there is formed a uniformly deformed region at the inner wall of the expanded tube end in the area of the recesses and between the expanding members and this region protrudes less into the interior as in the case of the absence of the ring. The pushing-on operation of the tube end onto the connecting member is facilitated thereby. Additionally, the self-reconvertible ring has the advantage of contributing to better holding together the expanding members and providing for the expanding members an additional restoring force in addition to that of the annular spring after withdrawal of the expanding cone.
It is particularly advantageous using an expanding tool in conjunction with connectors having connecting members which comprise the aforementioned holding elements including a sealing edge and wherein the recesses and rings at the expanding members are aligned to this sealing edge.
Specifically, the recesses at the expanding members may be axially arranged in a manner such that the sealing edge at the holding element is disposed symmetrically relative to Substitute Page IEPA/EP
-5a the recesses. If desired, there may be provided more than one recess at the expanding mandrel and more than one sealing edge at the connecting member.
In such construction of the expanding mandrel, a tube end region, when compared to the absence of the ring, is less but uniformly expanded and extends in circumferentially closed manner around its inner wall. This region experiences a small expansion and self-reconversion which does not impede the pushing-on operation during passage over the sealing edge of the connecting member. It is thereby ensured that, notwithstanding the gaps which arise between the expanding members during the expanding operation, at least this region of the tube end comes to firmly and sealingly engage the connecting member on both sides of the sealing edge around its entire inner circumference whereby a firm and sealing connection is formed in toto.
Brief Description of the Drawings Exemplary embodiments of the inventive expanding tool are illustrated in the drawings and will be explained and described in detail hereinbelow having regard to the reference characters. There are shown in Figure 1 a longitudinal section through an exemplary embodiment of the expanding tool according to the invention;
Figure 2 a cross-section through the expanding tool as shown in Figure 1 along the line II-II;
Substitute Page IEPA/EP
5b -Figure 3 a longitudinal section through a detail of Figure l;
Figure 4 a longitudinal section through a modified 5construction of the expanding tool as shown in Figure 1; and Figure 5 a view of a connector for use in conjunction with the expanding tool as shown in Figure 1 or Figure 4.
Preferred Embodiments of the Invention Figure 1 shows a longitudinal section through a first exemplary embodiment of an expanding tool including a housing 1 which contains at one end thereof actuating means 2 for actuating the expanding tool. In the illustrated Substitute Page IEPA/EP
exemplary embodiment the actuating means 2 comprise a pressure fluid operated piston 3 which is connected to expanding means in the form of an expanding cone 4 by means of, for example, a screw connection. Instead of the pressure fluid operated piston 3 there may also be provided different actuating means like, for example, mechanical actuating means. The pressure fluid may be axially or radially fed to the housing 1. The housing 1 may be provided with holding means permitting the housing to be held during operation; the housing is constructed such as to also permit overhead work.
At the opposite end of the housing 1 there is arranged a generally cylindrically shaped expanding mandrel 5. This expanding mandrel 5 contains an inner bore 6 comprising a conically shaped bore portion 7, which is engaged or can be brought into engagement with the expanding mandrel 4, and a cylindrical bore portion 8 in the free end thereof. At this free end, the expanding mandrel 5 is provided with a chamfer 9 which may extend at an angle in the range of 5~
to 20~ relative to the circumferential surface of the expanding mandrel 5. The edges which delimit the chamfer 9, are rounded. The chamfer 9 as well as its rounded edges prevent damages to the inner wall of the a tube end 19 into which the expanding mandrel 5 is inserted for expansion.
The expanding mandrel 5 is multiply subdivided in lengthwise direction and comprises a number of expanding members 10 which assume the shape of cylinder sectors; in the illustrated exemplary embodiment, see Figure 2, the expanding mandrel 5 is subdivided eightfold and thus comprises eight expanding members 10. In the inoperative or non-actuated condition of the expanding mandrel 1, the expanding members 10 engage each other in circumferential direction and thus define a generally cylindrical circumferential surface.
A thickened section 11 is formed at the inner end of the expanding mandrel 5 or at the inner ends of the expanding members 10, respectively. Holding members extend therefrom and thereby the expanding mandrel 5 is exchangeably held in the associated end of the housing 1. In detail, each one of the holding members comprises an arm 12 which radially projects from the circumference of the thickened section 11 and which is provided at its circumference with an accommodation 13 for receiving biassing means such as, for example, an annular spring 14. The annular spring exerts a radially inwardly directed bias on the expanding members 10 whereby the expanding members 10 are held in mutual engagement in the non-actuated condition of the expanding mandrel 5 and whereby the generally cylindrical circumferential surface of the expanding mandrel 5 is formed. The radially projecting arms 12 are radially displaceably placed in guide means at the associated end wall of the housing 1 and such guide means comprise a holding plate 15 and a bearing plate 16 provided with a slide element 17. The holding plate 15 is releasably mounted at the end wall of the housing by means of screws so that the expanding members 10 or the expanding mandrel 5, respectively, are exchangeably arranged at the end wall of the housing 1 by means of the radial arms 12 and the holding plate 15.
Respective recesses 18 are located at the expanding members 10 intermediate the thickened section 11 and the chamfer 9 and constructed such as to form a circumferential groove in the closed or non-actuated state of the expanding mandrel 5. Preferably, the edges of the recesses 18 are Substitute Page IEPA/EP
bevelled in order to avoid damages to the tube end 19 upon insertion of the expanding mandrel 5.
The longitudinally sectional illustration of Figure 3 shows in detail the expanding mandrel 5 and a ring 28 which is inlaid into the recesses 18. This ring completely or partially fills the recesses 18. It is made of an elastic material or a material which is self-reconvertible at ambient temperature and which, if desired, may be reinforced. Preferably, it is made of a material having a self-reconversion behavior which is comparable to that of the expanded tube end and likewise may consist of cross-linked polyolefin.
In this as well as the exemplary embodiment described hereinbelow, the members such as the expanding cone and the expanding members of the expanding mandrel which are subjected to high mechanical stress, are manufactured from high-order tool steel. There is thus prevented, on the one hand, the formation of frictions and seizures between the parts which act upon each other, and deformation of the expanding members under the action of high expanding forces, on the other hand.
In the upper half of Figure 1 the expanding tool is shown in the inoperative condition. In this condition, the expanding mandrel 5 merely is placed within the conically shaped bore portion 7 of the inner bore 6 of the expanding mandrel 5 and there is no axially directed force which acts upon the expanding cone 4. The expanding members 10 are, then, in mutual engagement and the expanding mandrel 5 forms a generally cylindrical body as shown in Figure 2.
Substitute Page IEPA/EP
Upon applying pressure to the piston 3, this piston and therewith the expanding cone 4 are displaced within the housing 1 towards the expanding mandrel 5. The expanding cone 4 is thereby forced into the conically shaped bore portion 7 whereby the expanding members 10 are urged apart in radial direction against the force of the annular spring 14. The lower half of Figure 1 shows the expanding cone 4 in the terminal position of its displacement path in which position the maximum expansion of the expanding mandrel 5 is achieved. During this expansion, the gaps which arise between the expanding members 10, are bridged by the ring 28 which is received within the recesses 18 of the expanding members 10 and which is expanded conjointly therewith.
For expansion of a tube end, the expanding mandrel 5 is inserted, in the inoperative condition of the expanding tool, into a tube end 19 of a material which preferably is self-reconvertible at ambient temperature such as, for example, cross-linked polyolefin. During such insertion, the end wall of the tube end 19 engages the thickened section 11 and thereby the axial length of the to-be-expanded tube end 19 is delimited. Upon actuating the expanding cone 4, the expanding members 10 are outwardly urged against the force of the annular spring 14 whereby the tube end 19 is expanded by a corresponding amount.
During this operation, the inner surface of the tube end 19 engages the outer surface of the expanding mandrel 5, however, not entirely in the region of the ring 28, which is received in the recesses 18 and bridges the gaps between the forced-apart expanding members 10. In correspondence therewith, there is formed at the inner wall of the expanded tube end 19 a section or land which extends in circumferential direction, which protrudes inwardly and Substitute Page IEPA/EP
-which has a height determined by the depth of the recesses 18, the thickness of the ring 28 and the extension of the expanded ring 28 in the region between the expanding members 5.
The significance of the ring 28 and the land formed thereby at the inner wall of the expanded tube end 19 will be recognized in view of the connector to which the expanded tube end 19 is connected by means of its self-reconversion. Such connector may be constructed, forexample, like the tube connector according to German Utility Model No. G9404513 and is illustrated in longitudinal section in Figure 5. The tube connector 20 defines a straight piece of tubing comprising connecting members 21 at its opposite ends. Each one of the connecting members 21 includes a holding element 22 for connection to an expanded tube end like the tube end 19. Each one of the holding elements 22 includes an outer surface 23 which gradually slopes towards the free end of the tube connector 21 and a sealing edge 24 which steeply slopes on the other side.
The recesses 18 of the expanding members 10 are aligned to the axial position of the sealing edge 24 at the connecting member 21 onto which the expanded tube end 19 is placed. Preferably, the sealing edge 24 is symmetrically disposed relative to the recesses 18 such that the lands, which remain at the circumference of the inner wall at the tube end 19 after expansion, also extend symmetrically relative to the sealing edge 24 in axial direction. These lands protrude inwardly to an extent less than in the absence of the ring 28 and thereby facilitate the pushing-on operation of the expanded tube end 19 onto the connecting member 21 across the sealing edge 24. Otherwise, Substitute Page IEPA/EP
however, the lands are also subject to a likewise reversible deformation for a short period of time. As a consequence, these lands will engage, after self-reconversion, the connecting member 21 on both sides of the 5 sealing edge 24 around its entire circumference whereby a firm and sealing connection between the tube end 19 and the connecting member 21 is obtained at least in this region.
Additionally, the ring 28 represents part of the biassing means since the presence of the ring 28 has the effect of 10 holding together the expanding members 10 of the expanding mandrel 5 and subjecting the same to a further restoring force in addition to that of the annular spring 14 after withdrawal of the expanding cone 4.
The connecting member 21 of the tube connector 20, if desired, may comprise more than one sealing edge 24; in such case, there are present more than one recess 18 at corresponding locations of the expanding mandrel 5.
Figure 4 is an illustration which corresponds to Figure 1 and shows a modified construction of the expanding tool.
Identical parts therein are denoted by the same reference characters. There will be recognized therein the housing 1 containing the actuating means 2 in the form of a pressure fluid operated piston 3 which cooperates with an expanding cone 4.
An expanding mandrel 25 includes an inner bore 26 which is of conical configuration throughout and extends along the entire axial length of the expanding mandrel 25.
Otherwise, also here the expanding mandrel 25 is composed of eight expanding members which are held together under the bias of an annular spring 14. The annular spring 14 is held in an accommodation 13 of radial arms 12 which extend Substitute Page IEPA/EP
-lla from a thickened .section 11 at the inner end of the expanding mandrel 25 and which are radially displaceably arranged at the end wall of the housing 1 between a holding plate 15 and a bearing plate 16 having a slide element 17.
The rounded edge of the expanding mandrel 25 is connected by means of a chamfer 9 to the remaining part of the expanding mandrel 25; at least one recess 18 is located intermediate the chamfer 9 and the thickened section 11 of the expanding members 10 and a ring 28 (not shown) is inlaid thereinto in correspondence with the showing of Figure 3. The function and mode of operation of this expanding tool correspond to those which have been described hereinabove with reference to Figures 1 to 3.
Substitute Page IEPA/EP
Claims (7)
1. Expanding tool for temporarily expanding tube ends made of cross-linked polyolefin, consisting of a generally cylindrically shaped expanding mandrel (5,25,27) which is provided with an at least partially conically shaped inner bore (6,26) and which is subdivided in axial direction into a multiple number of expanding members (10) substantially having the shape of a cylindrical sector, further consisting of respective holding members protruding from the outer circumference of the expanding members (10), biassing means acting upon the holding members for biassing the expanding members (10) into mutual engagement in order to form the generally cylindrically shaped expanding mandrel (5,25,27), recesses extending along the circumference of respective expanding members (10) between rounded free ends and the holding members, a housing (1) within which the holding members are radially displaceably guided, conically shaped expanding means (4) for engaging the at least partially conically shaped inner bore (6,26) of the expanding mandrel (5, 25,26), and actuating means (2) for reversibly axially displacing the expanding means (4) within the inner bore (6,26) of the expanding mandrel (5,25,27) and expanding the same against the force of the biassing means, characterized in that a ring (28) made of a material having a self-reconversion behavior comparable to that of cross-linked polyolefin, is received in the recesses (18).
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Substitute Page IEPA/EP
2. Expanding tool according to claim 1, characterized in that the material of the ring of the constitutes a reinforced material.
3. Expanding tool according to claim 1, characterized in that the ring is made of cross-linked polyolefin.
4. Expanding tool according to any one of claims 1 to 3, characterized in that the ring (28) substantially fills the recess (18).
5. Expanding tool according to claim 1, characterized in that each expanding member (10) comprises a chamfer (9) between the rounded free end and the recess (18).
6. Expanding tool according to claim 1, characterized in that the chamfer (9) is delimited by bevelled edges.
7. Expanding tool according to claim 1 for use with a connector comprising a connecting member (21) having at least one sealing edge (24), characterized in that the recesses (18) at the expanding members (10) are symmetrically aligned to the sealing edge (24) of the connecting member (21).
Substitute Page IEPA/EP
Substitute Page IEPA/EP
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE19504968.3 | 1995-02-15 | ||
| DE19504968A DE19504968A1 (en) | 1995-02-15 | 1995-02-15 | Spreading tool for cold forming |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2211897A1 true CA2211897A1 (en) | 1996-08-22 |
Family
ID=7753972
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002211897A Abandoned CA2211897A1 (en) | 1995-02-15 | 1996-02-07 | Expanding tool for cold forming |
Country Status (11)
| Country | Link |
|---|---|
| EP (1) | EP0809553A1 (en) |
| JP (1) | JPH11500358A (en) |
| AU (1) | AU4788196A (en) |
| CA (1) | CA2211897A1 (en) |
| DE (1) | DE19504968A1 (en) |
| FI (1) | FI973328A0 (en) |
| HU (1) | HUP9801997A2 (en) |
| NO (1) | NO973754L (en) |
| PL (1) | PL321799A1 (en) |
| SK (1) | SK110397A3 (en) |
| WO (1) | WO1996025255A1 (en) |
Families Citing this family (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE29613985U1 (en) * | 1996-08-13 | 1996-11-14 | Wirsbo Rohrproduktion und Vertriebs-GmbH, 63150 Heusenstamm | Spreading tool with return device |
| US6439023B1 (en) * | 2000-03-22 | 2002-08-27 | General Electric Company | Methods and apparatus for retrofitting compressible flanges |
| DE202008002266U1 (en) * | 2008-02-18 | 2008-04-30 | Novopress Gmbh Pressen Und Presswerkzeuge & Co. Kommanditgesellschaft | Device for expanding pipes |
| DE202008002265U1 (en) * | 2008-02-18 | 2008-04-30 | Novopress Gmbh Pressen Und Presswerkzeuge & Co. Kg | Device for expanding pipes |
| CH699306A1 (en) * | 2008-08-13 | 2010-02-15 | Finemon Ag | Flaring tool for pipes and pipe pressing clutch. |
| US11541581B2 (en) | 2016-09-02 | 2023-01-03 | Zurn Industries, Llc | Injection molded cold-expansion compression collar |
| US11543065B2 (en) | 2016-09-02 | 2023-01-03 | Zurn Industries, Llc | Extruded cold-expansion compression collar |
| US11054076B2 (en) | 2016-11-04 | 2021-07-06 | Zurn Industries, Llc | Reinforcing ring with sleeve |
| ES2948193T3 (en) * | 2018-09-27 | 2023-09-01 | Uponor Innovation Ab | Expansion tool |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3385087A (en) * | 1966-02-18 | 1968-05-28 | Huth Mfg Corp | Swaging tool |
| US4198844A (en) * | 1979-01-05 | 1980-04-22 | J & S Hydraulics Inc. | Tube expander |
| SE500665C2 (en) * | 1993-02-05 | 1994-08-01 | Wirsbo Bruks Ab | Method for establishing a pipe connection and for use in the process suitable pipe connection piece |
-
1995
- 1995-02-15 DE DE19504968A patent/DE19504968A1/en not_active Withdrawn
-
1996
- 1996-02-07 JP JP8524630A patent/JPH11500358A/en active Pending
- 1996-02-07 SK SK1103-97A patent/SK110397A3/en unknown
- 1996-02-07 AU AU47881/96A patent/AU4788196A/en not_active Abandoned
- 1996-02-07 WO PCT/EP1996/000501 patent/WO1996025255A1/en not_active Application Discontinuation
- 1996-02-07 PL PL96321799A patent/PL321799A1/en unknown
- 1996-02-07 EP EP96904006A patent/EP0809553A1/en not_active Ceased
- 1996-02-07 HU HU9801997A patent/HUP9801997A2/en unknown
- 1996-02-07 CA CA002211897A patent/CA2211897A1/en not_active Abandoned
-
1997
- 1997-08-14 FI FI973328A patent/FI973328A0/en unknown
- 1997-08-14 NO NO973754A patent/NO973754L/en unknown
Also Published As
| Publication number | Publication date |
|---|---|
| NO973754L (en) | 1997-10-13 |
| WO1996025255A1 (en) | 1996-08-22 |
| PL321799A1 (en) | 1997-12-22 |
| EP0809553A1 (en) | 1997-12-03 |
| JPH11500358A (en) | 1999-01-12 |
| DE19504968A1 (en) | 1996-08-22 |
| FI973328A (en) | 1997-08-14 |
| SK110397A3 (en) | 1998-01-14 |
| FI973328A0 (en) | 1997-08-14 |
| HUP9801997A2 (en) | 1998-12-28 |
| NO973754D0 (en) | 1997-08-14 |
| AU4788196A (en) | 1996-09-04 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| FZDE | Discontinued |