US3580020A - Apparatus for calibrating pipes - Google Patents

Abstract

Apparatus for calibrating pipes by expansion or swaging, comprises a housing holding an annular deforming tool consisting of a number of axially extending segments which are arranged side-by-side to form a cylinder and which are movable radially outwards or inwards, this radial movement being limited by stops which engage the ends of the segments, and a cylindrical sleeve which bears on either the inner or the outer faces of the segments and which forms a pressuretight chamber between itself and the housing, so that, in use, when the chamber is supplied with fluid under pressure the sleeve is forced radially outwards or inwards, hence forcing the segments radially outwards or inwards into engagement with the inside or outside of a pipe until further radial movement is prevented by the stops, at which time the pipe is expanded or swaged to an exact size determined by the apparatus.

Description

United States Patent 3,344,634 10/1967 Ellenburg 442,579 12/1890 Grimes 3,461,712 8/1969 l-lenkel et al inventors Ali Bindernagel Dusseldorf-Gerresheim;

Erwin Kost, Osterath; Karl-Hans Staat,

Homberg Bie Ratingen, Germany Appl. No. 754,759

APPARATUS FOR CALIBRATING PIPES l 1 Claims, 13 Drawing Figs.

U.S. CI 1 72/393, 72/402 Int. Cl B21d 39/08 Field of Search 72/58, 393, 394, 399, 402, 400, 60-63 References Cited UNITED STATES PATENTS Primary Examiner-Richard J. Herbst Assistant Examiner-Michael J. Keenan Attorneys-Curt M. Avery, Arthur E. Wilfond, Herbert L.

Lerner and Daniel J. Tick ABSTRACT: Apparatus for calibrating pipes by expansion or swaging, comprises a housing holding an annular deforming tool consisting of a number of axially extending segments which are arranged side-by-side .to form a cylinder and which are movable radially outwards or inwards, this radial movement being limited by stops which engage the ends of the segments, and a cylindrical sleeve which bears on either the inner or the outer faces of the segments and which forms a pressuretight chamber between itself and the housing, so that, in use, when the chamber is supplied with fluid under pressure the sleeve is forced radially outwards or inwards, hence forcing the segments radially outwards or inwards into engagement with the inside or outside of a pipe until further radial movement is prevented by the stops, at which time the pipe is expanded or swaged to an exact size determined by the apparatus.

Patented May 25,1971 3,580,020

P atented May 25, 1971 3,580,020

10 Sheets-Sheet 2 Fig.2

7 A N- h Fig. 2a

Patented May 25, 1971 3,580,020

10 Sheets-Sheet 5 Fig.3

Patented May 25, 1971 10 Sheets-Sheet 5 Patented May 25, 1971 10 Sheets-Sheet 6 Patented May 25, 1971 10 Sheets-Sheet 7 S V R Patented May 25, 1971 10 Sheets-Sheet 8 :A\\ m w a M \& hh S Q? Patented May 25, 1971 3,580,020

10 Sheets-Sheet 9 Patented May 25, 1971 3,580,020

10 Sheets-Sheet 1O 0. LII/1," 0 o J I M m I Fig.10

' 10a a I00 I Fig. ll I16 5 5 APPARATUS FOR CALIBRATING PIPES The deviations of the roundness from an exact circular section of pipes which are unavoidable in the production of large pipes, are frequently so great that satisfactory welding together of pipe sections of nominally equal diameter is not possible. For this reason such pipes are mechanically brought to an equal intended diameter and exact roundness by expansion or swaging, called calibration.

Since conformity of the mutually abutting pipe ends is sufficient for satisfactory welding together of pipe sections, calibration is often limited to relatively short lengths at the ends of the pipe sections. However the necessity can also arise for pipes to be permanently expanded or swaged by a specific amount over the entire length, for example for the strainhardening of the pipe material, and in the case of welded pipes for the reduction of the welding stresses or in order to achieve smooth-walled pipe conduits.

In the following description of the invention, by calibration there is to be understood not only a variation of the pipe diameter by predetermined amounts .for the purpose of achieving precise pipe diameters, but any variation of pipe diameter with simultaneous correction of form if necessary.

Various forms of apparatus are known for calibrating pipes, especially pipe ends. One form has a deforming tool which consists essentially of an externally cylindrical bush, divided by axial planes into a number of segments-as many as with a tapered bore and an axially displaceable mandrel of frustopyramidal form having a number of sides corresponding to the number of segments, with radial and axial stops for the segments. Such a calibrating apparatus is secured on a stand which is displaceable and securable on base frame. It has the disadvantage that the surface pressure exerted by the tapered inner surfaces of the segments upon the side surfaces of the frustopyramidal mandrel is greater by the ratio of the mandrel diameter to the pipe diameter than the radial pressure of the outer segment surfaces upon the pipe wall necessary for expansion. Furthermore, on account of the inclination of the tool surfaces sliding on one another in displacement towards the mandrel axis, the radial pressure between them increases over the length of the calibre segments from the large end face to the smaller end face of the frustopyramidal mandrel, in inverse proportion to the end surface diameters.

in the expansion of pipes by drawing the mandrel into the axially supported calibre bush, the danger exists that when a certain expansion pressure is exceeded the surface pressure between the surfaces of the bush and the mandrel sliding on one another may become too great and these parts of the apparatus wear prematurely and tend to seize, this being helped by any dust and dirt which have penetrated. Similar difficulties occur in the disengagement of the tool from the workpiece. These phenomena are the reason why expansion devices of this kind are operated only with relatively small surface pressures and are used only for the calibration of pipes of materials of low strength and having small wall thicknesses in relation to the diameter.

A further essential disadvantage of the apparatus consists in that the calibre segments, rounded-off externally according to the final internal diameter of the pipe, rest at the beginning of the expansion operation only with their longitudinal edges on the inner wall of the pipe and come gradually into full abutment with the pipe inner wall only with increasing expansion, with the consequence that in the region of these edges the flow limit of the pipe material is exceeded sooner than in the pipe wall parts lying between them so that an irregular material expansion is produced over the pipe periphery. Consequently with this apparatus expansion of the pipe periphery for the purpose of material strengthening is not possible, since for this purpose a uniform material expansion must be required over the full periphery.

Since data as to pipe dimensions always relate to the external diameter and pipes of equal nominal diameter can have wall thicknesses differing considerably from one another, furthermore, for the expansion of pipes of given external diameter, special calibre bushes are needed for each pipe wall thickness, since otherwise the pipes do not become uniformly round.

In another form of known apparatus, for the expansion of pipes over their entire length a pressure liquid is pumped into the pipe which is sealed at the ends, the occurrence of inaccuracies of roundness is avoided due to the fact that a cylindrical mould of length corresponding to the pipe length is arranged around the pipe, and the pipe is expanded until it uniformly abuts the inner wall of the mould. With this apparatus the pipe is also tested at the same time for fluidtightness. This apparatus is not capable of working without the outer mold since on the use only of internal pressure an irregular deformation and nonround pipes would result from inequalities of the wall thickness and of the material flux.

This expansion and calibrating apparatus has the further disadvantage that an external mould of length corresponding to the pipe length must be available for every pipe diameter and a considerable quantity of liquid must be available for the filling of the pipes.

Moreover, the use of the apparatus requires much time both for the preparation of the individual expansion operations by sealing off and introduction of the pipe to be expanded into the mould cylinder, for the connection of the liquid conduits, the filling and emptying of the pipe and for the pressing off and expansion itself. Use of this apparatus on building sites where pipes are laid and connected into conduits is hardly possible on account of its dimensions, its weight and the circumstances connected with its operation.

According to this invention an apparatus for the calibration of pipes by expansion or swaging comprises a housing holding an annular deforming tool consisting of a number of axially extending segments which are arranged side by side to form a cylinder and which are movable radially outwards or inwards, this radial movement being limited by stops which engage the ends of the segments, and a cylindrical sleeve which bears on either the inner or the outer faces of the segments and which forms a pressuretight chamber between itself and the housing, so that, in use, when the chamber is supplied with fluid under pressure the sleeve is forced radially outwards or inwards, hence forcing the segments radially outwards or inwards into engagement with the inside or outside of a pipe until further radial movement is prevented by the stops, at which time the pipe is expanded or swaged to an exact size determined by the apparatus.

In contrast to the previous apparatus, that of the present invention can be used to calibrate pipes at comparatively low expense, is relatively small and light, the parts of which are hardly subject to wear in operation, which is simple to operate, permits a rapid manner of working and produces better results.

When the apparatus is in the form of an expansion apparatus the annular sleeve bears upon the inner surfaces of the segments and the pressure is applied to the sleeve from the interior; whereas when the apparatus is a swaging apparatus the sleeve encloses the cylindrical tool assembled from the segments and the pressure is applied to the outer side of the sleeve.

In order to ensure reliable and rapid lifting away of the deforming tool from the workpiece again after every working stroke, the segments are preferably biased permanently, or are arranged to be biased temporarily, radially in an opposite direction to that in which they are moved when the chamber is pressurized. In the case of a swaging apparatus this return bias may be supplied by leaf springs inserted into the gaps between adjacent segments of the deforming ,tool. Preferably the housing has a pair of annular flanges which abut the opposite ends of the segments and form guides for the radial movement of the segments, and each segment has at each of its ends a shoulder which projects into an annular groove in the adjacent housing flange, one of the axially extending walls of each groove forming a' stop which engaged by the shoulders to limit the operative movement of the segments.

In this case a permanently acting return bias can be applied as yieldable force by a tension or compression spring initially stressed in the peripheral direction and bearing upon the shoulders at the ends of the segments. A temporarily acting return bias may be provided by each shoulder having a radially extending flange which projects into an annular recess in the wall of the groove which forms the stop, an annular seal extending round the radially extending flanges and forming a pressuretight chamber within the recess, this chamber being pressurized to return the segments when the pressure in the chamber between the housing and the sleeve is relaxed.

In the case. of variation of the pipe diameter on only a part of the pipe length, in order to provide a gradual transition from the defonned pipe part to the underformed pipe part, the segments may be bevelled at one end of the deforming tool.

Thus the feed movement of the workpiece to the tool is at the same time facilitated.

The axial extension of the part of the segments defined by axially parallel longitudinal edges corresponds at least to the pipe end to be reshaped to precise diameter and exact roundness. Such an apparatus of short constructional length in comparison with the pipe length can also be used for the reshaping of pipes over their whole length if they and a holding device for the pipe are arranged to move relatively to one another in the axial direction.

Such an apparatus intended for the expansion of pipes would have to be secured on the free end of a sufficiently long overhang arm which is clamped at one end on a support, and which is movable with the apparatus intermittently into the pipe to be expanded, or intermittently over the pipe if the pipe is to be swaged.

An apparatus for swaging pipes may be arranged in a fixed or axially mobile housing which is open at both ends, through which the pipe is pushed intermittently, or which is itself intermittently moved over the pipe which is held fast at one end.

The apparatus may also include an abutment for the pipe part to be deformed, the abutment taking up the deformation pressure and determining the final form of the pipe, and consisting either of a ring coaxially surrounding and spaced from the deforming tool or of a mandrel arranged coaxially within and spaced from deforming tool.

Various examples of apparatus in accordance with the present invention are now described with reference to the accompanying drawings, in which:

FIG. 1 is an axial longitudinal section through one-half of one example of an apparatus for calibrating pipes by expanslon;

FIG. 2 represents a partial cross section through the apparatus shown in FIG. 1 along the line A-A;

FIG. 2a represents a plan view of the externally visible part of several segments of the deforming tool of the apparatus shown in FIGS. I and 2;

FIG. 3 is a similar view to that of FIG. 1, but showing the apparatus with an abutment ring surrounding the deforming tool;

FIG. 4 is a similar view to that of FIG. I but showing a further example for calibrating pipes by expansion;

FIG. 5 is an axial longitudinal section through one-half of an example of an apparatus for calibrating pipes by swaging;

FIG. 6 is a similar view to that of FIG. 5, showing the apparatus with an abutment mandrel arranged within the deforming tool of the apparatus;

FIG. 7 is a similar view to that of FIG. 5, but showing a further example;

FIG. 8 is a longitudinal section showing the apparatus of FIG. 4 together with a sealing and clamping head attached to a pipe end to test pressuretightness of the pipe;

FIG. 9 is a side elevation, in part longitudinal section, of an example of an apparatus for the expansion of pipes in which the pipe can be moved step by step over the expansion apparatus; 7

FIG. 10 is a similar view to that of FIG. 9, but showing an example of an apparatus for swaging pipes;

FIG. 11 illustrates an example of an apparatus for swaging pipes, in which the swaging device is arranged on a frame which is movable in an axial direction along a unilaterally firmly clamped-in pipe; and

FIG. 12 shows an example of an apparatus for the simultaneous calibration of both ends of a pipe in which a calibrating apparatus is pushed on to each of the ends of the pipe which is supported in the middle.

In the example shown in FIGS. 1, 2 and 2a, the deforming tool consists of a number of segments 1, which form a cylinder around the cylindrical body 4, with thin leaf springs 2 or 2 inserted as spacing members into the gaps between them, which lie in axial planes. The segments 1 and leaf springs 2, 2' have shoulders at their ends lawhich project with mutually facing annular grooves 4b, 5b in annular flanges 4a, 5 extending radially from the external periphery of the housing body 4. A cylindrical sealing sleeve 3 of rubber-elastic material lies against the inner surfaces of the segments 1 and leaf springs 2, with its ends bearing tightly against the end faces of the guide grooves 4b, 5b and forms with the peripheral surface 40 of the housing body 4 an annular chamber 30 of variable volume tightly closed off on all sides. This chamber can be served with a fluent material under pressure through a passage 7 in the body 4. Tensioned annular springs 6 countersunk on the shoulders In of the segments I urge the segments radially inwards into their rest position in which their outer surfaces lie flush with the peripheries of the flanges 4a, 5. However, when the chamber 3a is pressurized the sleeve 3 and hence the segments 1 are pushed radially outwards, the segments engaging the part of a pipe 10 which is pushed over the flanges 4a, 5. The maximum amount by which the pipe part is then expanded on further pressurizing the chamber 3a is determined by the width of the grooves 4b, 5b, the outer axially extending walls of which serve as stops for the segment shoulders la, and hence for the segments themselves. After the removal of the pressure from the chamber 311 the springs 6 return the segments 1 into their initial rest position against the force of the leaf springs 2, 2' lying between them. The housing 4, 5 is secured on the free end of an overhang arm 8 which is clamped at its other end to a support and which is sufficiently long for a pipe to be expanded along its whole length by pushing it bit by bit over the expanding apparatus, provided that the part 10a to be expanded is longer than the effective length of the segment 1.

If only pipe ends corresponding to or shorter than the length of the segments 1 are to be expanded, a stop 4d, which may be adjustable is the axial direction, can be provided on the periphery of the housing flange 4a.

The other housing flange 5 consists for reasons of assembly of a ring 5 detachably connected with the housing body 4, the ring being sealed with the latter by packing rings 50.

In the example shown in FIG. 3 the apparatus in FIGS. 1, 2, 2a is fitted with an abutment ring 9 which surrounds the housing 4, 5 and forms an annular gap between it and the housing for receiving the pipe to be expanded. The inner diameter of the ring 9 is the same as the external diameter to which the pipe is to be expanded. The ring 9 can be arranged in common with the support for the overhang arm 8 on a chassis which is either fixed or mobile in the axial direction (not shown).

The calibrating apparatus shown in FIG. 4 differs from that shown in FIGS. 1 and 2 essentially only in that the segments 41 and the sealing sleeve 43 are not returned by springs but hydraulically or pneumatically into their rest position after pressure is released from the chamber 430. For this purpose the shoulders 41a of the segments 41 are provided with annular radially outwardly extending flanges 41b which project into annular recesses 46a in the outer walls of the grooves receiving the shoulders 41a. In the recesses 460 the flanges 41b are surrounded by a U-shaped se sling sleeve 46. The segments 41 are returned into their rest position by gas or liquid pressure introduced after every working stroke into the annular recesses 46a behind the sealing sleeves 46.

The annular recesses 46a are connected through passages 45b, 44b and conduits 40a and 40b with a container 40 which is filled with gas or liquid under pressure. In every expansion operation the fluid is expelled from the annular recesses 46a into the container 40, from which it flows back into the annular recesses 46a after relaxation of the expansion pressure and moves the segments 41 with the sleeve 43 back into their rest position.

' The housing of the apparatus shown in this example consists, for constructional reasons, of several detachably interconnected parts. Flange rings 45 with interposed packing rings 45a are placed upon both ends of an externally cylindrical body 44. Ring nuts 49 with inwardly directed flanges 4% which, together with the mutually facing end faces of the rings 45 form the annular recesses 46a, are screwed on to the flange rings 45.'The inner peripheral surfaces of the flanges 49b here form the outer stops for the shoulders 41a of the segments 41. The rings 45 are sealed with the ring nuts outside the openings of the passages 45b by packing rings which ensure a pressuretight closure for the annular recesses 46a. The introduction of fluid under pressure into the chamber 450 takes place through a radial passage 47 in the body 44. I

The expanding apparatus shown in FIG. 4 is in fact more expensive to construct than those shown in FIGS. 1 and 3, but offers the advantage that the retraction of the deforming tool proceeds substantially more quickly and consequently more working strokes in a set time can be obtained. The quicker manner of operation has an especially favorable effect in the calibration of relatively large pipe lengths.

The apparatus shown in FIG. 5 is intended for the calibration of pipes by swaging. The segments 51 here lie with the sleeve 53 externally enclosing them in an inner recess of the housing 54 which is limited at one end by an inwardly directed flange 54a of the housing 54 and at the other end by a ring 55 pushed into the end of the housing 54. Between the sleeve 53 and the housing 54 is formed a pressuretight chamber 53a. Annular flanges 54b and 55b projecting axially towards each other from the flange 54a and the ring 55 respectively form guides for the end edges of the segments 51 and stops for the shoulders at sector ends 510. Fluid under pressure is supplied to the chamber 530 through a bore 540 in the housing body 54.

Sealing rings 55a between the housing body 54 and the ring 55 prevent the escape of fluid from the pressure chamber 53a.

The calibrating apparatus shown in FIG. 6 differs from the example of FIG. 5 only in that an abutment mandrel 60 for'the pipe 10 to be deformed is arranged coaxially with the housing 54, 55. This mandrel determines the internal diameter of the pipe part 10b which is to be deformed. The return of the segments 1 is effected here by the leaf springs 2 arranged between them (similar to those shown in FIGS. 2, 2a). To support and assist in returning the segments, outwardly acting annular springs 66, are arranged on the shouldered ends of the segments 51. The abutment mandrel 60 is secured on an overhang arm 68. v

In the example of calibrating apparatus shown in FIG. 7, which otherwise corresponds to the example shown in FIG. 5 or 6, the return force of the leaf springs 2, 2 is supplemented in a manner corresponding to that in the example of FIG. 4, i.e. by hydraulic or pneumatic pressure which acts in annular recesses 760 through U-shaped sealing sleeves 76, 76 accommodated therein upon annular flanges extending inwardly from the shoulders of the segments 71. Here again for construction reasons the housing is assembled from several parts 74, 75, 79 sealed from one another by sealing rings. The pres sure chambers 76a behind the sealing sleeves 76 resting on the shoulders 710 are connected, like the pressure chambers 460 shown in FIG. 4, to a pressurized container (40) fluid.

FIG. 8 shows a particular example of an expanding apparatus with the features of the present invention, which permits, together with the calibration of pipe ends, the testing of pipes for fluidtightness and strength by the introduction of fluid under pressure into the pipe which is closed tightly at both ends. The apparatus is assembled substantially like that shown in FIG. 3. However, here the annular gap receiving the pipe end 105 to be expanded, between the abutment ring- 89 and the housing 84, 85, is closed off at one end by an end plate 82 bolted to the ring 89 and the housing body 84. The housing body 84 is provided with a connection 840 for the test pressure liquid conduit. A packing ring 85c lies in a peripheral groove of the flange ring 85, and is forced against the inner wall of the pipe 10 by the pressure of fluid introduced behind it through passages 84b, 85f, and 85d.

In the example represented diagrammatically in FIG. 9 a complete apparatus for the expansion of pipes is shown the expansion apparatus being secured on the free end of a fixed overhang arm 98. An abutment ring 99 surrounding the apparatus 90 is fixed onto an immovable chassis 96. In front of and behind the expanding apparatus 90 there are resiliently supported rollways 94, 95, by means of which a pipe 10 to be expanded can be fed to the apparatus 90 and if desired moved over it.

In the example shown in FIG.10, calibrating apparatus 100 for swaging pipes is arranged in a fixed housing 106. An abutment mandrel 60 is secured on the free end of a fixed overhang arm 8. Here again resiliently supported rollways 104, serve for the feed of a pipe 10 to the calibrating apparatus 100 and possibly for the intermittent further movement of the pipe between the indiw'dual reshaping operations.-

In the example shown in FIG. 11 a calibrating apparatus is arranged with its housing 116 on a trolley 114 which is mobile in the axial direction, with the aid of which it can be shifted on to the pipe 10 to-be reshaped which is fixed on a retaining device 115. A calibrating mandrel 60 secured on an overhang arm 108 of appropriate length is also mountedon the trolley 1l4-and is moved along the pipe with the calibrating apparatus. The mandrel 60 is axially displaced against a spring 116 on striking the retaining device 115.

The apparatus represented diagrammatically in FIG. 12 enables the simultaneous calibration of both ends of a pipe 10. Two calibrating apparatuses 120 are arranged with their housing 126 on trolleys 124 which are mobile in the axial direction in relation to a device 125 for resiliently supporting and holding the middle part of the pipe 10. Calibrating 'mandrels 128 are also mounted on the trolleys 124.

In place of the apparatuses 100, 110, 120 represented in the examples shown in FIGS. 10, 11 and 12, for swaging pipes apparatuses for the expansion of pipes may be used instead, even those which-as for example the apparatus shown in FIG 8- -are also used for the testing of pipes for fluidtightness.

In all the examples shown in the drawings, at one end of the deforming tool the ends of the segment faces remote from the faces on which the sleeve acts are bevelled, i.e. tapered towards the end of the tool, so that in operation a gradual transition from the deformed pipe part 18 the undeformed part is obtained.

We claim:

1. Apparatus for calibrating pipes by expansion or swaging, comprising a housingformed with a pair of spaced annular flanges, and an annular deforming tool held on said housing, said deforming tool comprising a multiplicity of axially extending segments each having a radial dimension greater than the circumferential dimension thereof and having a relatively narrow spacing from one another, means mounting said segments on said housing side by side in the space between said annular flanges to form a cylinder and so that said'segments are movable radially with respect to said housing, stop means for engaging the ends of said segments to'limit the radial movement of said segments, cylindrical sleeve means located within said space between said annular flanges and being in sealing engagement at the respective ends thereof with said annular flanges, said sleeve means bearing on one of the faces of said segments and defining a pressuretight chamber between itself and said housing, and means for supplying fluid under pressure to said chamber, whereby, when said chamberis supplied with fluid under pressure, said sleeve and hence said segments are forced to move radially away from said housing into engagement with the wall of a pipe placed radially adjacent said housing and deform said pipe in the vicinity of said segments until further radial movement is prevented by said stop means, at which time said pipe is deformed to an exact size determined by the apparatus.

2. Apparatus as set forth in claim 1, for calibrating pipes by expansion, wherein said cylindrical sleeve means on the inner faces of said segments and when said fluidtight chamber between said sleeve and said housing is supplied with fluid under pressure, said sleeve and hence said segments are forced radially outwards to expand said pipe which is placed over said housing.

3. Apparatus as set forth in claim 1, for calibrating pipes by swaging, wherein said cylindrical sleeve means bears on the outer faces of said segments and when said fluidtight chamber between said sleeve and said housing is supplied with fluid under pressure, said sleeve and hence said segments are forced radially inwards to swage said pipe which is placed within said housing.

4. Apparatus as set forth in claim 1, wherein leaf springs are position between adjacent members of said plurality of segments so that said segments are held evenly in place peripherally around the cylinder which they form.

5. Apparatus as set forth in claim 1, wherein at one end of said deforming tool the ends of the faces of said segments remote from the faces on which said sleeve bears are tapered towards said end of said deforming tool.

6. Apparatus as set forth in claim 1, including means biasing said segments radially in a direction opposite to that in which they are moved when said fluidtight chamber is supplied with fluid under pressure, for returning said segments to their rest positions when said fluid pressure is removed from said fluidtight chamber.

7. Apparatus for calibrating pipes by either one of expansion and swaging, comprising a housing, and an annular deforming tool held on said housing, said deforming tool consisting of a plurality of axially extending segments, means mounting said segments on said housing side by side to form a cylinder and so that said segments are movable radially with respect to said housing, stop means for engaging the ends of said segments to limit the radial movement of said segments, cylindrical sleeve means bearingon one of the faces of said segments and defining a pressuretight chamber between itself and said housing, means for supplying fluid under pressure to said chamber, whereby, when said chamber is supplied with fluid under pressure, said sleeve and hence said segments are forced to move radially with respect to said housing into engagement with the wall of a pipe placed radially adjacent said housing and deform said pipe in the vicinity of said segments until further radial movement is prevented by said stop means, at which time said pipe is deformed to an exact size determined by the apparatus, means biasing said segments radially in a direction opposite to that in which they are moved when said fluidtight chamber is supplied with fluid under pressure, for returning said segments to their rest positions when said fluid pressure is removed from said fluidtight chamber, said housing being provided with a pair of annular radially extending flanges, mutually facing faces of said flanges abutting the opposite ends of said segments and forming guides for the radial movement of said segments, and each of said mutually facing faces containing wall means defining an annular groove, and each of said segments being provided at each of its ends with shoulder means which project into said annular grooves, the axially extending walls of said wall means defining said annular grooves remote from said cylindrical sleeve forming said stop means.

8. Apparatus as set forth in claim 6 wherein said biasing means acts upon said shoulders at the ends of said segments.

9. Apparatus as set forth in claim 7, wherein each of said axially extending walls fonning said stop means contains further wall means defining an annular recess, said shoulders at each end of said segments being provided with a radially extending flange pro ecting into the corresponding annular recess, an annular seal means extends around said radially extending flange in said annular recess and forms a pressuretight chamber within said recess, and there is provided means for supplying fluid under pressure to said chamber in each of said annular recesses when the pressure in said chamber between said housing and said cylindrical sleeve is released, so that said segments are returned to their rest positions.

10. Apparatus as set forth in claim 1, including a cylindrical abutment surface coaxial with said cylinder formed by said segments and spaced radially apart from the operative faces of said segments of said deforming tool, the annular gap between said segments and said abutment surface receiving said pipe to be calibrated.

11. Apparatus as set forth in claim 10, including means for tightly closing said annular gap between said segments and said abutment surface at one end, means defining an annular groove in the peripheral surface of said housing at the other end of said annular gap, an annular packing ring in said annular groove, and means for supplying fluid under pressure to the bottom of said annular groove to force said packing ring outwards with respect to said groove against a pipe which is inserted into said annular gap to form a seal so that said pipe can be tested for fluidtightness at the same time as it is calibrated.

Claims (11)

1. Apparatus for calibrating pipes by expansion or swaging, comprising a housing formed with a pair of spaced annular flanges, and an annular deforming tool held on said housing, said deforming tool comprising a multiplicity of axially extending segments each having a radial dimension greater than the circumferential dimension thereof and having a relatively narrow spacing from one another, means mounting said segments on said housing side by side in the space between said annular flanges to form a cylinder and so that said segments are movable radially with respect to said housing, stop means for engaging the ends of said segments to limit the radial movement of said segments, cylindrical sleeve means located within said space between said annular flanges and being in sealing engagement at the respective ends thereof with said annular flanges, said sleeve means bearing on one of the faces of said segments and defining a pressuretight chamber between itself and said housing, and means for supplying fluid under pressure to said chamber, whereby, when said chamber is supplied with fluid under pressure, said sleeve and hence said segments are forced to move radially away from said housing into engagement with the wall of a pipe placed radially adjacent said housing and deform said pipe in the vicinity of said segments until further radial movement is prevented by said stop means, at which time said pipe is deformed to an exact size determined by the apparatus.

2. Apparatus as set forth in claim 1, for calibrating pipes by expansion, wherein said cylindrical sleeve means on the inner faces of said segments and when said fluidtight chamber between said sleeve and said housing is supplied with fluid under pressure, said sleeve and hence said segments are forced radially outwards to expand said pipe which is placEd over said housing.

3. Apparatus as set forth in claim 1, for calibrating pipes by swaging, wherein said cylindrical sleeve means bears on the outer faces of said segments and when said fluidtight chamber between said sleeve and said housing is supplied with fluid under pressure, said sleeve and hence said segments are forced radially inwards to swage said pipe which is placed within said housing.

4. Apparatus as set forth in claim 1, wherein leaf springs are position between adjacent members of said plurality of segments so that said segments are held evenly in place peripherally around the cylinder which they form.

5. Apparatus as set forth in claim 1, wherein at one end of said deforming tool the ends of the faces of said segments remote from the faces on which said sleeve bears are tapered towards said end of said deforming tool.

6. Apparatus as set forth in claim 1, including means biasing said segments radially in a direction opposite to that in which they are moved when said fluidtight chamber is supplied with fluid under pressure, for returning said segments to their rest positions when said fluid pressure is removed from said fluidtight chamber.

7. Apparatus for calibrating pipes by either one of expansion and swaging, comprising a housing, and an annular deforming tool held on said housing, said deforming tool consisting of a plurality of axially extending segments, means mounting said segments on said housing side by side to form a cylinder and so that said segments are movable radially with respect to said housing, stop means for engaging the ends of said segments to limit the radial movement of said segments, cylindrical sleeve means bearing on one of the faces of said segments and defining a pressuretight chamber between itself and said housing, means for supplying fluid under pressure to said chamber, whereby, when said chamber is supplied with fluid under pressure, said sleeve and hence said segments are forced to move radially with respect to said housing into engagement with the wall of a pipe placed radially adjacent said housing and deform said pipe in the vicinity of said segments until further radial movement is prevented by said stop means, at which time said pipe is deformed to an exact size determined by the apparatus, means biasing said segments radially in a direction opposite to that in which they are moved when said fluidtight chamber is supplied with fluid under pressure, for returning said segments to their rest positions when said fluid pressure is removed from said fluidtight chamber, said housing being provided with a pair of annular radially extending flanges, mutually facing faces of said flanges abutting the opposite ends of said segments and forming guides for the radial movement of said segments, and each of said mutually facing faces containing wall means defining an annular groove, and each of said segments being provided at each of its ends with shoulder means which project into said annular grooves, the axially extending walls of said wall means defining said annular grooves remote from said cylindrical sleeve forming said stop means.

8. Apparatus as set forth in claim 6 wherein said biasing means acts upon said shoulders at the ends of said segments.

9. Apparatus as set forth in claim 7, wherein each of said axially extending walls forming said stop means contains further wall means defining an annular recess, said shoulders at each end of said segments being provided with a radially extending flange projecting into the corresponding annular recess, an annular seal means extends around said radially extending flange in said annular recess and forms a pressuretight chamber within said recess, and there is provided means for supplying fluid under pressure to said chamber in each of said annular recesses when the pressure in said chamber between said housing and said cylindrical sleeve is released, so that said segments are returned to their rest positions.

10. Apparatus as set forth in claim 1, includIng a cylindrical abutment surface coaxial with said cylinder formed by said segments and spaced radially apart from the operative faces of said segments of said deforming tool, the annular gap between said segments and said abutment surface receiving said pipe to be calibrated.

11. Apparatus as set forth in claim 10, including means for tightly closing said annular gap between said segments and said abutment surface at one end, means defining an annular groove in the peripheral surface of said housing at the other end of said annular gap, an annular packing ring in said annular groove, and means for supplying fluid under pressure to the bottom of said annular groove to force said packing ring outwards with respect to said groove against a pipe which is inserted into said annular gap to form a seal so that said pipe can be tested for fluidtightness at the same time as it is calibrated.

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