BENDING A PLURALITY OF PIPES OR LIKE ELONGATE MEMBERS AS AN ASSEMBLY

Abstract: A method of, and apparatus for, bending pipes or like elongate members (38, 40), wherein a plurality of the pipes or members (38, 40) is arranged in substantially parallel relation with one another to form an assembly, either in side-by-side contact or with spacer means (138) therebetween, with a region of said assembly at which a bend is to be formed being located in a cavity (36) formed between two co-acting form tools (28, 34), the cavity (36) conforming closely to the curvature required of the assembly and constraining the pipes or members (38, 40) substantially against relative lateral movement; and one of the form tools (34) is movable relative to the other form tool (28) and toward the end of the assembly, the bend produced in the pipes or members (38, 40) of the assembly conforming to the contour of the other form tool (28) while allowing relative axial or longitudinal movement of the pipes or members (38, 40) at least at said region.

Description: BENDING A PLURALITY OF PIPES OR LIKE ELONGATE MEMBERS AS AN ASSEMBLY This invention relates to the bending of elongate members, and in particular, to the bending of a number of such - 5 members as or in an assembly. The invention has particular application to elongate tubular members. As the practical applications for the invention more typically involve such members, the following largely is directed to these. However, it is to be understood 10 that the invention also is applicable to non-tubular elongate members, such as bars or rods. In many situations, a plurality of elongate members is used in an assembly in which, over at least a portion of their length, the members of the assembly are closely positioned 15 in side-by-side longitudinal relationship. Typically, the members of the assembly are similarly bent in two or three dimensions so that the assembly conforms to a surface of a supporting structure. Such conformity may for example, be required for two or more tubes defining part of a system, for 20 example a.hydraulic system of a vehicle in which the tubes may be required to be bent for close conformity to that surface and required to be in closely juxtaposed side-by-side relationships for ease of connection of the system. Practice in the art is for elongate members to be 25 bent individually. They then are formed into the required assembly for positioning against, and connection to, the support surface. The two or three-dimensional forms required ■ for the closely juxtaposed side-by-side assembly can not be preci achieved because bending is performed individually and, as a 30 consequence, the members are not sufficiently complementary to permit their precise interfitting—particularly at the bend itself wherein each individual member is to achieve its own radius of curvature within the assembly. There previously have been proposed devices which, 5 while inten »ded for individual bending of elongate members, could be used for simultaneous bending of two or more members. However, such devices frequently are such that all simultaneously bent members would have substantially the same, rather than complementary, curvature and so can not be formed into an accurately i terfitting assembly. Alternatively, they are such that while each elongate member is bent to a respective curvature, this is performed with the members in spaced relationship such that subsequent interfitting still is necessary and accuracy of interfitting still is less than desirable. Examples of such arrangements are illustrated in U.S. patent specif cations 78,418; 828,338; 888,727; 1,891,861 and 1,899,281 and in Australian patent specifications 200,092 and. 295,715. Currently, effort in the art is being directed to increasing the precision of bending so that overall efficiency is increased, to provide assemblies in which interfitting of elongate members consequently is more accurate. However, even with automated machinery controlled by data processors , bending of elongate members continues to be performed individually and so necessitates subsequent formation of the assembly. Also, while bending of individual members can be effected more efficiently with such apparatus, the accuracy of interfitting of the members of the resultant assembly remains less than desirable. Individual bending of the members has been practiced for many years due either to inability of workers to bend elongate members as an assembly in a satisfactory manner, or to a belief that this was not possible. We have found that elongate members can be bent as an assembly and that this can be performed both, efficiently and to a high degree of precision. We have found elongate members can be bent by a method in which a plurality of the members is positioned with the members in substantially parallel relationship at a required longitudinal positioning one to the other(s) , and the members subjected as an assembly to a required bending operation. In such method, the members are held in such relationship so that adjacent ones are constrained against lateral movement relative to each other. ~ According to the invention, there is provided a method of bending a plurality of pipes or like elongate members to conform to a common path as an ass π±>l 7 wherein the unbent pipes are arranged in side by side relation with one another to form an assembly or group, with the region o said group to be bent located within a cavity formed between two co-acting form- tools such that the cross-section of the cavity conforms 5" closely to the periphery of the group of pipes, the group is gripped on the work side of the cavity to prevent relative lateral movement of the pipes with respect to one another during bending, and one of the form-tools is moved relative to the other and along the pipes towards the stock end thereof to 0 force the pipes to bend as an assembly so that the assembly conforms to the contour of the other form-tool, the individual pipes being free to move with respect to one another at least at said region. In that method and as used herein, the "work side" of the cavity denotes that side thereof from which the form tool acts to force the pipes to bend. Also, the "stock end" of the pipes denotes the end thereof toward which the form tool moves during a bend forming operation, i.e. the end toward which the bend is formed. The "stock side" of the cavity thus denotes the side thereof nearer to the stock end of the pipes i.e. the side of the cavity facing toward that stock end. The invention also provides a method of bending a plurality of pipes or like elongate members to conform to a common path as an assembly, wherein the pipes are arranged in side by side relation with one another in a group, said group is bent as a unit between form-tools at a first bending station and the said group then is bent as a unit in a second bending station while the pipes of the group are held against relative lateral movement at said first station and are allowed to move relative to one another between the form tools at said first t station and at the stock, or unbent, side of said second station. The invention additionally provides a method of bendin pipes or like elongate members, wherein a plurality of the members is .arranged in substantially parallel relation with one another to form an assembly, with a region of said assembly at which a bend is to be formed being located in a cavity formed between two co-acting form tools, the cavity conforming closely to the periphery of the assembly and constraining the pipes substantially against relative lateral movement; and one of the form-tools is moved relative to ' the other and toward the end of the assembly toward which the bend is formed to bend the pipes in the assembly to conform to the contour of the other form-tool while allowing relative longitudinal adjustment of the pipes between said form-tools. The invention still further provides apparatus for bending pipes or like elongate members, having two co-acting form tools mounted on support means so that one of the form-tools is movable relative to the support means? the form-tools forming therebetween a cavity through which a plurality of pipes can extend in side by side relation with one another so as to form an assembly such that the cross section of the cavity conforms closely to the periphery of the assembly; the form-tools being so movable that, with a region of the assembly to be bent located in the cavity and the assembly gripped to prevent relative lateral movement of the pipes with respect to one another, the one form-tool is movable relative to the other form-tool and. along the pipes towards one end thereof to force the pipes to bend, as an assembly so that the assembly conforms to the contour of the other form-tool. In one form, at least a portion of one of the form-tools can be movable between a closed position for gripping the region of the assembly to be bent, and an open position enabling the plurality of pipes to comprise the assembly to be received in the cavity and positioned in side by side relation The apparatus may include two or more work stations at each of which is mounted respective such co-acting form-tools with the two form-tools at each station forming a respective such cavity. The stations may be mutually spaced such that the assembly, when bent at one station, moves the one end of the pipes so as to be receivable in the cavity at the next station, and so on; this arrangement being such that, with the pipes still held against relative movement at the one station, a further required bend then can be formed at the next station. The invention enables bending of a plurality of elongate members, such as tubular members, into a wide variety of con¬ figurations. ' Thus, for example, with the members positioned in relationship with their axis in, or their out-surface contacte by, a common plane, the members can be simultaneously bent parallel to that plane. Alternatively, the members can be bent out of such common plane but so that the axis of each remains in a respective plane perpendicular to the common 5 plane. In a further alternative, capable of a number of variants, the members can be simultaneously bent into a composite of the first two types of configuration. Moreover, it is to be understood that the invention is applicable to a plurality of elongate members of which one or more is of 10 a different diameter or section to the others. During a bending operation, some degree of relative longitudinal movement of the elongate members on the stock side of the form-tools occurs between elongate members bent through different radius of curvature. This is a 15 natural consequence of the different path length followed by respective elongate members in the bend formed. However, for most efficient bending, it is desirable that the elongate members be restrained against relative longitudinal movement on the work side of the form-tools. The elongate members can 20 be so restrained by gripping forces exerted by the form-tools. Alternatively, the elongate members can be so restrained on the work side of the form tools by use of any suitable clamping device, either releasable or permanent, or by the elongate members being secured on the work side of the form 25 tools by soldering or use of a suitable glue or adhesive. While restraint against relative longitudinal movement on the work side of the form is desirable for efficient bending, it is not necessary that the plurality of elongate members to be bent be constrained against longitudinal movement 30 as an assembly. Indeed, it is found that allowing or causing limited longitudinal movement, in the direction in which the bend is to be formed, can facilitate efficient, precision bending. Such limited movement can be allowed by the gripping forces exerted by the form tool being limited such that, while 35 those forςes substantially prevent .relative lateral movement of the elongate members, they permit the members as an assembly to be drawn through the cavity by .the bending forces exerted by the form tools. Alternatively, the elongate members can be pulled or pushed as an assembly during a bending operation, by any suitable , means, so ^ as to move longitudinally in the direction in which the bend is being formed to a limited extent and at a controlled rate. 5 In one embodiment of the methods of the invention, the cavity is defined by a groove extending inwardly of and around a curved peripheral surface of the other form-tool and a side face of the one form-tool, the pipes and tools being positioned so that the periphery at said region of the assembly 0 is engaged between opposed walls of said groove and between the base of said groove and said side face, with said end of the pipes being spaced beyond the tools, the one tool being movable to draw said side face around the groove and bend the pipes as an assembly to conform to the contour of said groove. 5 In that embodiment, the other tool may have two parts separable on a plane substantially parallel to said groove, said parts being moved together to bring said opposed walls into engagement with said pipes, the pipes being arranged in at least one layer in which the pipes are substantially in a common plane Q parallel to the plane on which said parts are separable, and movement of 'the one tool relative to the other tool bending the pipes as an assembly parallel to said separable plane. The parts may be moved to engage said pipes in a single said layer, at least one of said opposed walls being stepped, pipes 5 of different section being engaged by said opposed walls. In a preferred form of the methods, said form tools each comprises a roller, said cavity being defined by a respective curved peripheral surface of each tool and by a respective radial flange of each tool, the pipes and tools ° being positioned so that the periphery of said region of the assembly is engaged between said respective surfaces and between said respective flanges, with said end of the pipes being spaced beyond the tools, the one tool being moved around the other tool with the axes of the tools parallel and bending the pipes as an assembly to conform to the contour of the respective surface of other tool. The pipes may be arranged in at least one layer in which the pipes are substantially in a common plane extending be said flanges, movement of the one tool relative to the other tool bending the pipes as an assembly out of said plane. In the methods, the pipes may be arranged in. side-by- side contact and bent as an assembly in such contact. Alternatively, spacer means may be provided between adjacent ones of at least some of the pipes, said spacer means being bent with said pipes. In a further preferred form of the methods, said co-acting tool comprises respective overlapping discs mounted for movement toward each other to define said cavity there¬ between, and away from each other to enable arrangement of the pipes therebetween with said end of the pipes spaced beyond the tools, each disc having a family of curved slots therein with each slot of one family overlapping a respective slot of the other family, the one tool having associated therewith a parallel family of spacer plates of complementary curvature to said slots and movable so that each passes through a respective slot of the one tool, through the cavity and through a respective slot of the other tool to divide the cavity into a family of curved channels, the pipes being arranged in parallel spaced relation between said tools and gripped thereby in said cavity such that each pipe in said cavity is off-set from said slots, and wherein the spacer plates are moved as a unit through said slots and cavity so that an edge of each engages and moves along a respective pipe toward said end thereof and bend the pip to conform to the contour of the respective spacer plate and of a respective channel. Each such spacer plate may have a leading edge in such movement which extends helically with respect to the direction of movement of the plates, the leading edges being moved on complementary guide surfaces to provide in such movement a component around the slots so that engagement of each plate with a respective pipe to bend the latter is by means :of a side edge of the plate. Alternatively, each spacer plate may have a leading edge in such movement which extends helically with respect to the direction of movement of the plates, the plates being moved perpendicular of the discs so that the extent of each plate in the direction of the slots progressively increases and so that engagement of each plate with a respective pipe to bend the latter is by means of the leading, edge. In one embodiment of the apparatus, the cavity is defined by a groove extending inwardly of and around a curved peripheral surface of the other form-tool and a side face of the one form-tool with the one tool being mounted for movement relative to the other tool so that said side face is able to ride around said peripheral surface, the groove having opposed walls adapted to engage the periphery of the assembly therebetwee and the base of the groove and said side face being adapted to engage the periphery of the assembly therebetween. In that embodiment, said other tool may have two parts separable on a plane substantially parallel to said groove, said parts bein movable to bring said opposed walls into engagement with said pipes at the periphery of said assembly. Said other tool may be a roller, said groove extending around the circumference thereof, said groove being stepped to provide radially inner and outer portions of said groove each of which has a respective spacing between said opposed walls so that pipes of respective sections can be engaged between said-opposed walls. In one preferred form, each tool of the apparatus may comprise a roller, said cavity being defined by a respective curved peripheral surface of each tool and by a respective radial flange of each tool, the tools being positioned so that respective surfaces are radially spaced and the one tool is movable around the other tool with the axes of the tools parallel and the flanges axially spaced. Tn a further embodiment, said co-acting tools comprise respective overlapping discs mounted for movement toward each other to define said cavity therebetween, and away from each other, each disc having a family of parallel curved slots therethrough with each slot of one family overlapping a respective slot of the other family, the one tool having associated therewith a family of parallel spacer plates of complementary curvature to said slots and movable perpendicularly of said discs between a retracted position and an operative position, each plate in movement to its operative position passing through a respective slot of the one tool, through the cavity and a respective slot of the other tool to divide the cavity into a family of curved channels, the arrangement being such that with a plurality of pipes gripped in said cavity in parallel relation with each pipe being off-set from the slots in said cavity and having said end thereof, beyond the tools, the spacer plates can be moved as a unit to their operative position to divide the cavity into said channels such that during, movement to that position an edge of each spacer plate engages and moves along a respective pipe towards - 5 said end of the latter and bend the pipe to conform to the contour of the respective spacer plate and of a respective channel. In the further embodiment, each spacer plate may have a leading edge in movement toward its operative position 10 which edge extends helically with respect to the direction of that movement of the plates, at least one slot of at least one of said families thereof defining a guide surface engaged by the leading edge of the respective spacer plate such that during movement of the plates to the operative 15 position a component of movement around the slots is imparted to the plates as a unit so that each plate is adapted to engage with and bend a respective pipe by means of a side edge of the plate. Alternatively, each spacer plate may have a leading edge in movement toward its operative position which edge extends 20 helically with respect to the direction of that movement, the movement- being perpendicular with respect to the discs and the inclination of the edges with respect to the discs being such that the extent of each plate in the direction of the slot progressively increases so that the leading edge of each 25 plate is adapted to engage and bend a respective pipe. The members may be in the desired parallel relationship by adjacent ones thereof being in side-by-side contact along at least a portion of their length at which a bend is to be formed. However, in an alternative arrangement, 30 adjacent elongate members may be in the desired parallel relationship by each being in side-by-side contact with a spacer means located therebetween. In one form of that alterna a respective spacer means can be located between the elongate members of some, but not all, pairs thereof; with 5 the other elongate members of the assembly being in side-by-side contact. The spacer means for an adjacent pair of elongate members may itself be of elongate form similar to that of the elongate members. If of such form, the spacer means is disposed in parallel relationship between the elongate members of its pair and, while such spacer means may be of a length substantially equal to its pair of elongate members, it alternatively may have a length sufficient only to space the elongate members of its pair over the portion of the length of the latter at which a bend is to be formed. In the case of a spacer means of such elongate form, it is bent with the elongate members between which it is located. Thus, in such case, the plurality of elongate members and the, or each, spacer means is subjected to a bending operation as an assembly. The or each spacer means of elongate form may itself be a tube, bar or rod of circular section. However, it also can be of non-circular section, such as square. The or each spacer means may be of the same cross-sectional area as at least one of the elongate members between which it is located, or of greater or lesser area. Iri either form for providing the elongate members in side-by-side contact, it is found that the present invention enables bending of the elongate members, not only as an assembly, but also with substantially no spring-back of the members when bent. Elongate members such as pipes or tubes exhibit a significant degree of spring-back, i.e. partial unbending, after they are bent individually or separately by prior art methods. However, when bent as an assembly, either in side-by-side contact or in such contact via spacer means located between adjacent elongate members, it is found that the precision bend provided by the invention is retained due to a substantial absence of spring-back. In one arrangement, a principal one of the form- tools may be a roller having, around at least a portion of its circumference, a slot in which the plurality of members is receivable in a required side-by-side relationship. The slot is defined by an opposed pair of side walls and, extending between the side walls, a radially inner wall. The spacing b etween the side walls is chosen, or is adjustable, so th those walls provide lateral support for the elongate members in the required relationship. • The inner wall defines the inner radius of a bend to be formed and to which the curvature of at least one of the members, when bent, * 5 is to correspond. A simple form of such roller can be used to bend a plurality of members such as tubes so their axes or descriptors are retained in a single plane. For tubes of a common diameter, the spacing between the side walls 10 of the slot is such,,that the tubes can be received between, and be laterally supported by, those walls. The depth of the slot i.e., the radial spacing of the inner wall from the circumference of the roller, is such as to enable the plurality of tubes to be received successively in the slot 15 in side-by-side relation. It is found that with rotation of the roller relative to the other or secondary form-tool, such as a further roller or a block member, bearing against the outermost tube, the bending force or movement generated between the secondary form tool and that outermost tube 20 is transmitted through successive tubes to the innermost one, and the' tubes thereby are bent as an assembly. The innermost tube is found to be bent into close conformity with the inner wall of the slot; while successive tubes are bent with a high degree of precision 25 around the next innermost tube. The contact maintained between adjacent tubes and the close spacing of the side walls of the slot are found to substantially prevent deformation of the tube section. The simple arrangement described in the preceding 30 paragraph provides an "in plane" bend having a uniform curvature for a single layer of tubes. In one variant, an in plane bend with a constantly increasing or decreasing radius of curvature can be provided by the simple expedient of using such slotted principal roller in which the radius of curvature of the inner wall varies correspondingly. In a further variant, such bend of constant or varying curvature can be simultaneously provided in a plurality of tubes arranged in at least two layers by corresponding increase in the spacing between the opposed side walls of the slot; with each layer having at least one tube. In this variant each of the side walls may provide direct lateral support for only the tubes in the adjacent outermost layer where there are more than two layers, although the tubes of the or each inner layer will be indirectly supported laterally by contact between tubes of adjacent layers. The tubes of adjacent layers may have their axes aligned perpendicular to the layers, or they may be axially offset within a regular geometric arrangement. Where, in the arrangement of the preceding paragraph, there are two or more layers each of one tube, the members of each layer in fact initially have their axes or other longitud- inal descriptors in a ccεmon set of parallel planes perpendicular to the direction in which the bend is to be formed. There thus results an "out of plane" bend. In a still further variant the slot of the principal tool, in addition to extending circumferentially of the roller, may be inclined with respect to the axial extent of the roller. In this case, the arrangement can be such that, with a plurality of tubes in a single layer bounded by the side walls of the slot, the tubes can be bent as an assembly so that the bend has both an in plane and an out of plane component in the manner of part of a simple, flat or ribbon-like helix. Alternatively the slot may be such that, although having a medial line around its inner face in a plane perpendicul to the roller axis, the side faces progressively diverge uniforml from an initial zone in which those faces are parallel to such plane. In.this case, a layer of a plurality of tubes successivel received in the slot can be bent in a manner which approximates to an in plane bend but with the layer being progressively twiste ; " through the bend with respect to the longitudinal extent of the tubes. It also is possible to employ a composite of the alternatives provided by this and the preceding paragraph such that the slot, and the resultant configuration of the plurality of tubes when be'nt, approximates to part of a twisted helix. In such arrangement for the principal forming tool, it may not be practical for that tool to be of integral construction. This is because slight deformation of the section of the elongate members occurs during bending and this, in conjunction with the initial lateral support to be provided by the side walls of the slot, results in the bent members being so firmly gripped between those side walls as to be difficult to release. It therefore is highly desirable that the principal forming tool be of at least two part construction such that, after a bending operation, the spacing between the side walls of the slot can be increased. Thus, for example, the principal forming tool may be of two parts separable on a plane or, in more complex forms of the tool, a curved surface extending adjacent one or intermediate each of the side walls. However, in an alternative arrangement, the principal forming tool may be of three part construction in which each of the side walls of the slot is defined by a respective plate member having a central bore with a third member in the form of a pin passing through the bore of each plate member. Such pin may be cylindrical and define the radially inner wall of the slot. For a two part principal forming tool for use with elongate members of a fixed section or groups of sections, the two parts may be pivotally mounted for movement between an assembled position permitting a bending operation and a disassembled position enabling removal of a plurality of bent elongate members. For the three part principal forming tool construction, the plate members may be axially movable between such assembled and disassembled positions. Spacer members may be insertable between the plate members to enable a change in the spacing between the side walls of the slot in the assembled * tool, or substitute pins can be provided for this purpose. In either construction, it is preferable that the parts or plate members of the principal forming tool in their assembled Oositior.s.. and ar. τ ' can be used for this. In the foregoing description,of arrangements for the principal forming tool it " is largely implicit that the side walls of the slot are substantially parallel. However, it is to be understood that this is not necessary. Thus, the slot may have mutually inclined side walls to enable it to receive elongate members of progressively increasing section. Alternatively, at least one of the side walls of the slot may be radially stepped to enable it to receive a first elongate member or group of members of a first diameter and at least one elongate member f greater section. There may be one radial step in at least one side wall of the slot to enable elongate members of two different sections to be simultaneously bent. However, there may be more than one such step so that elongate members of more than two different sections can be " simultaneously bent. Each side wall of the slot may be stepped in a complementary manner so that elongate members of different sections can be positioned and retained with their axes co-planar. In one convenient arrangement for providing an in plane bend in a plurality of tubes of at least two different sections, the radial step(s) in at least one side wall of the slot may be such that the spacing between the side walls is less over a radially inner portion of the slot than over a radially outer portion. As will be appreciated, this will necessitate that at least one radially innermost tube of the plurality of tubes as bent is of lesser diameter than at least one radially outermost tube. The arrangement may be such that the radial width of the innermost portion of the slot is sufficiently in excess of that required to receive the, or each, tube of the lesser diameter such that a shoulder defined by the step acts as an abutment for the tube(s) of greater diameter when bent as required. Such shoulder thus acts to prevent bending of the tube(s) of greater diameter beyond the required curvature and thereby prevents deformation of the tube(s) of lesser diameter which otherwise could occur. In the foregoing, reference is made to the principal forming tool being in the nature of a roller. However, .it will be appreciated that, in general, bends of somewhat less than 360° will be required, and it therefore is to be understood that the principal forming tool may simply comprise a member having slot'formed in a curved surface around which bending occurs, with the slot and surface being of lesser angular extent than - 5 360°. Also, as previously indicated, the bend to be imparted by such slot and surface can be other than one having a constant radius of curvature. The secondary forming tool can take a variety of forms, its principal function being to react forces applied 10 to the plurality of elongate members during a bending operation. However, the secondary forming tool also may provide a guiding function in serving to hold the elongate members prior to and/or during such operation. Also, as relative movement is required between the principal forming tool and the 15 secondary forming tool, with it being possible for either or both of them to move, the term "forces" is to be understood in that context. The secondary forming tool may be in the form of a roller or, as with the principal forming tool, it may simply 20 comprise a member having a curved surface of less than 360° angular extent. Alternatively, the secondary tool may simply comprise a member with a substantially flat bearing surface for bearing against the plurality of elongate members at the radially outward opening of the slot of the principal forming 5 tool. However, for providing a guiding function, the secondary tool may have a groove in which the plurality of elongate members are received in a similar manner to the slot of the principal forming tool. With relative movement between the secondary tool and 0 the principal forming tool, the arrangement is to be such as to constrain the plurality of elongate members to bend around and progressively be received in the slot of the principal forming tool. In such movement, the peripheral bearing surface, or a corresponding surface within the groove, of the secondary tool 5 is drawn longitudinally relative to the elongate members and angularly relative to the slot of the principal- forming tool. In one form of the secondary tool, the bearing surface may be defined by the periphery of a flange receivable in the slot of the principal forming tool. In such case, a shoulder on one or each side of the flange can be provided to ride over an external surface of the principal forming tool, -adjacent the slot, to limit the radial extent to which the flange extends into the slot.- In a variant of that form of the secondary tool, a groove may extend radially inwardly of the flange, from the bearing surface of the latter. Such arrangement is well suited to providing an in plane bend in which at least one larger diameter elongate member is to be located radially inwardly of at least one lesser diameter elongate member; the lesser diameter member(s) being received in and guide in bending by the groove, with the larger diameter member(s) being constrained to bend by the bearing surface. In a further form of the invention, each forming tool includes a plate or disc member; with the discs being mounted in parallel overlapping relation and defining therebetwee a cavity for the plurality of pipes or like elongate members to be bent. The discs are held in such relation by means of a centrally disposed shaft extending perpendicularly of the discs. At least one disc is movable along the shaft relative to he other disc to enable the discs to be moved together for gripping a plurality of pipes extending through the cavity, laterally of the shaft, and to enable the discs to be separated. Each of the discs has extending therethrough a family of parallel curved slots extending angularly around the shaft, with each slot of one disc overlying a respective slot of the other disc. One of the tools also includes a family of parallel spacer plates. The spacer plates are curved angularly around, and parallel to the longitudinal extent of, the shaft and complementary to the respective families of curved slots. The family of spacer plates are movable, as a unit, longitudinally with respect to the shaft so that a leading edge of each plate can be inserted through a respective slot of its disc, so as to pass into and across the cavity defined between the discs and then through a respective slot of the other disc. In such movement, the spacer plates divide the cavity into a series of channels extending angularly around the shaft, each channel being defined radially of the shaft by successive spacer plates and longitud¬ inally of the shaft by the two discs. The leading edge of each spacer plate most conveniently is shaped so as to extend helically with respect to the shaft; either -along a true helical path or an approximation thereto. Such leading edge of each spacer plate can extend between side walls of the plate spaced angularly with respect to the shaft; the side edges, for example, extending parallel to the shaft. The arrangement is such that each spacer plate has an acute angled corner defined between the leading edge and one side edge which leads, and an angled corner defined between the leading edge and the other side edge which trails, during movement of the spacer plate so as to extend through a respective slot defined in each disc and through the cavity. As a consequence, the extent of each spacer plate angularly with respect to the shaft which is located within the cavity increases from a minimum value to a maximum value as that movement progresses, and the angular length of the channels correspondingly increases. In use of the just described form of the apparatus, the spacer plates first are retracted and the discs are separated. A plurality of pipes or like members are placed between the discs and the discs then are moved together to grip the pipes in the cavity. The pipes are arranged, and are so gripped, so as to be in parallel, spaced relation and in substantially a common plane parallel to the discs. The spacing between the pipes is such that, within the cavity,- each pipe is intermediate a respective portion of successive slots of each disc through which the leading corners of successiv spacer plates are to pass. That is, within the chamber, the pipes are off-set from portions of the slots so that the leading corner of each spacer plate can pass between successive pipes. However, it will be appreciated that as the pipes are straight prior to bending and the slots are curved, each pipe will traverse at least one slot adjacent or beyond the cavity. The spacer plates then are moved as a unit so as to pass the leading edge of each plate through each disc and the cavity therebetween, with each spacer plate passing between successive pipes. With continuation of that movement, each spacer plate bears against the one of the pipes between which it passes that is nearer the shaft and constrains that pipe tα- r bend • . 18. progressively into conformity with the curvature of the spacer plate. The spacer plates as a unit thus bend the pipes as an assembly to provide an in plane bend in which each pipe has the curvature of a respective spacer plate and a respective one of the channels defined within the cavity by the spacer plates. The leading edge of each spacer plate can be helically inclined from the leading corner in either direction. In one arrangement those edges are inclined away from the pipes in an angular direction opposite to that in which the bend is to be 10 formed. In that one arrangement, the leading edge of at least one spacer plate may be guided, during movement of the spacer plates as a unit, by a complementarily inclined end of a respective slot of at least one of the discs. That guidance preferably is such that the spacer plates move angularly of, 15 in addition to'longitudinally with respect to, the shaft such that the side edge of each spacer plate adjacent the leading corner moves along and constrains a respective pipe. In an alternative arrangement, the leading edges of the spacer plates are inclined away from the pipes in the angular direction in which the bend is to be formed; that is, toward the stock end of the pipes to which the bend is to be form The side edge of at least one spacer plate may be guided, during movement of the spacer plates as a unit, by a complementary end wall of a respective slot of at least one of the discs, but AJ this need not be such that the spacer plates move angularly with respect to the shaft. Rather, it is the leading edge of each spacer plate which, because of its inclination, moves along a respective pipe and constrains the latter to conform to the curvature of the spacer plate. 0 In the alternative arrangement, the one of the discs through which the leading edges pass to enter the chamber may have a cam surface engaging the leading edge of an outermost spacer plate. Due to this engagement, that one of the disc can be rotated on the shaft, relative to the other disc, 5 to facilitate bending of the pipes. In each alternative, one or other of the discs most conveniently carries a series of locating members or ribs spaced laterally with respect to the shaft. These are spaced to facilitate initial positioning of the pipes to be bent in the above described spaced relation in which they are gripped in the cavity on movement of the discs together. In one form of operation according to the invention, the plurality of elongate members, which normally will be substantially straight, are arranged adjacent a work station at which the bending device is located. The elongate members are arranged in the required side-by-side relation with the location of each from which the bend is to extend being positioned, as required, and the members then are presented in such relationship to the slot of the principal forming tool. Prior to bending, the members are secured, such as by a clamp, to one side of the bending device, this being the side away from which the bend is to be formed; with the elongate members being free to adjust longitudinally to the other side of the device during a bending operation. The secondary tool then is positioned, if necessary, and a bending operation per¬ formed simultaneously on all of the elongate members, such as by drawing the secondary tool around the principal forming tool. Where a succession of similar bends is to be formed at required locations along the plurality of elongate members, the latter may simply be moved longitudinally to the one side of the bending device to present the next adjacent location to the device, and the bending operation repeated. The successive locations can be positioned in turn against a marker on or adjacent the bending device. Prior to each successive bending operation, it may be desirable to re-clamp or further clamp the plurality of members adjacent the one side of the bending device. Additionally or alternatively, it is possible to secure the members in the required relationship at each newly formed bend by soldering, bonding or welding, such as at a newly formed bend. Where successive bends of differing forms are required, these can be similarly formed by presenting the pluralit of members i,n turn to further work stations or by replacing the bending device usedfor the first bend with successive devices each appropriate to a particular one of the bends required. Description now is directed to the accompanying in which: Figure 1 shows a plan view of one form of bending device; Figure 2 shows a sectional view taken on line II-II of Figure 1; Figures 3 to 9 show alternative arrangements for formi tools suitable for use in a device as in Figures 1 and 2; Figure 10 shows a sectional view through a second form of bending device; Figure 11 is a sectional view taken on line XI-XI of Figure 10; Figure 12 is a developed, circumference view taken at line XII-XII of Figure 10; Figure 13 is an isometric view showing one component of the device of Figure 10; Figure 14 is a partial respective view along arrow XIV of Figure 11; Figure 15 shows a modified form of the device of Figures 10 to 13, in a view corresponding to that of Figure 10; Figure 16 is a view corresponding to ' that of Figure 11 / showing the modified device of Figure 15? Figure 17 is a view corresponding to that of Figure 14, taken along arrow XVII of Figure 16; Figure 18 is a view corresponding to Figure 13, showin a complementary form of the component as used in a modified form of the device of Figure 10; and Figure 19 corresponds to Figure 12 and shows a device as in Figure 10 as modified for use with the component of Figure With reference to Figures 1 and 2, the device 10 inclu a base plate 12 having a cover plate 14 mounted thereon for pivo in the directions of arrow A by means of hinge pin 16 extending through plate 14 and a side flange 18 of plate 12. Extending across the upper surface of plate 14 there is a lever arm 20 pivotable horizontally on vertical pin 22; with the latter proj ing through plates 12,14 and being secured below plate 12 by cla pin 24 releasably located in taper slot 26. The arrangement is such that in the device as illustra plates 12,14 are secured in parallel spaced relationship, with a 20 rotatable on plate 14 in the directions indicated by arrow B. However, by removal of pin 24, plate 14 can be pivoted upwardly on pin 16. With plate ' 14 pivoted upwardly, it is desirable for pin.22 and plate 14 to be retained in assembly; with arm 20 also secured. This can be achieved by pin 22 being • 5 a tight fit in the bore of plate 14. Alternatively, a transverse locating pin 27 can be inserted horizontally through plate 14 to locate in a transverse bore through pin 22. Between plates 12,14 there is a cylindrical, two-part 10 principal forming tool 28, having upper and lower parts 30,32 which define at their junction a slot 36 around part of the circumference of tool 28. Each of parts 30,32 has a central bore 33 through which pin 22 extends. However, part 30 is bolted to plate 14 and part 32 is bolted to plate 12 so as to 15 be fixed against rotation on pin 22. When plate 14 is pivoted upwardly from plate 12, parts 30, 32 are similarly separated and the lower end of pin 22 is tapered to facilitate this. Adjacent the periphery and in contact with tool 28, there is a secondary forming tool 34. As shown, this is in 20 the form of a block pivotable on one end of arm 20 so as to run on tool 28 during pivoting of arm 20 with face 35 bearing against tool 28 across slot 36. In an alternative form, tool 34 may comprise a roller. In Figures 1 and 2, tool 28 is illustrated schematical 25 A practical form of this, for providing an in plane bend in two smaller diameter bars and one larger diameter bar, is shown in Figure 3 in which corresponding parts have the same reference numerals as used in Figures 1 and 2. As shown in Figure 3, tool 28 defines around its periphery a slot 36, which is closed by to 3 0 34 to define a cavity. The spacing across slot 36 is such as to provide lateral support for smaller diameter rods 38 as well as for larger rod 40, due to each of the side walls of slot 36 being stepped. Shoulders 42 defined by the stepped side walls define an abutment for rod 40 when rods 38 are received in the 35 slot. Movement of tool 34 around tool 28 causes rods 38,40 to be -drawn into slot 36 and bent simultaneously as an assembly to a high degree of precision; with the innermost rod 38 conforming to the curvature of the base of slot 36 and" each other of rods 38,40 conforming closely to the preceding rod. With rods 38,40 extending through slot 36 and retained therein by tool 34, the latter can readily be caused to move around tool 28 by an appropriate force applied to the end of arm 20 remote from tool 34. The direction of that force and rotation can, with the arrangement illustrated, be in either of directions B. Figure 4 shows a similar arrangement to Figure 3. However, in this instance, the slot- 44 is not stepped and neatly receives a plurality of rods 38 of the same diameter. Also, the secondary tool is, in this instance, a roller 46 of reduced axially extent so as to be neatly received in slot 44. An alternative arrangement, producing a bend in which * 5 rod 40 represents the innermost member and rod 38 the outermost of the assembly involves simply the interchanging of the tools 28 and 34 as described in Figure 3, in the device shown in Figures 1 and 2. Release of the bent assembly on opening of ' the device would, however, require the pin in arm 20 to be 10 releasable in the manner of pin 26 as drawn. A further alternative, for providing an out of plane bend, is shown in Figure 5, in which the principal forming tool 50 and secondary forming tool 52 are of complementary form. Each of tool 50 and 52 has a respective roller portion 54,56 and, 15 at opposed ends, a respective peripheral flange 60,62. Tools 50 and 52 have their roller portions 54,56 spaced so that the flange portions enclose a slot 64 in which a number of similar bars 66 are receivable for simultaneous bending around roller portion 54. 20 The alternative of Figure 5 can be used in an arrangement as shown in Figures 1 and 2. In this, tool 50 can be mounted between plates 12,14 with pin 22 passing through its bore 68; while tool 52 can be rotatably mounted on and movable with arm 20 and plate 14. 25 In Figure 6, there is shown an arrangement intermediate the arrangements of Figures 3 and 5 in which parts corresponding to those figures are identified by the same reference numerals. In this instance, upper part 30 of tool 28 is of lesser radius than lower part 32. Also, tool 34 has a roller portion 56 and, 30 extending radially of the latter, a flange portion 62 which overl part 30. The inter-relationship is such that tools 28,34 cooperate in the manner of Figure 5 so that they together define slot 36. Elongate members 38 are received within the portion 35 of slot 36 t defined between parts 30,32; while larger diameter member 40 is received within the remainder of slot 36 so as to be constrained by roller and flange portions 56,62 of tool 34, by shoulder 42 of portion 30 and by portion 32. If tools 28,34 are mounted in a device as in Figure 1, with tool 28 on pin 22 and tool 34 rotatable on arm 20, an in plane bend with member 40 radially outermost can be formed. The tools 28,34 can -be modified to enable tool 34 to be mounted on pin 22 and tool 28 to be rotatably mounted on arm 20 to provide a similar bend but with member 40 radially innermost? although the arrangement of Figure 7 is preferable for such bend. The arrangement of Figure 7 is a composite of that of Figures 3 and 5, and can produce a bend which is the complement of that of Figure 6. However, portions 54,60 of tool 50 merge through an arcuate surface 70 to increase surface contact with larger diameter elongate member 40. Also, flange portion 62 is shaped to provide a shoulder 72 for similarly contacting member 40; while smaller diameter elongate members 38 are constrained between flange portion 60 and the radially inner extent of flange portion 62. Member 40 can be radially innermost or outermost in the bend, depending on which of tools 50,52 is located on pin 22 and arm 20 (Figure 1) , respectively. Such interchangeability has two practical advantages; firstly, greater productivity C an be achieved from a given set of tools and, secondly, since neither tool 28 nor tool 34 requires separation to release the bent assembly, there is no need for the pin in arm 20 to be releasable. Figure 8 shows a further modified form of the Figure 5 arrangement, suitable for producing a composite bend in elongate members of similar diameter. In this, forming tools 74,76 are of complementary conical form; each having a roller portion defining a conical surface 78,80 and, at its larger diameter end, a flange portion 82,84. With a respective one of tools 74,76 on pin 22 and arm 20 (Figure 1), the tools cooperate such that surfaces 78,80 and flange portions 82,84 define a conical slot 86 in which members 73 are received. Rotation of one tool around the other then results in the member 73 being bent as an assembly in an out of plane conical form corresponding to the radially inner one of surfaces 78,80. Where an assembly of elongate members with axes in a common plane is presented to tools 74,76, operation of the device of Figures 1 and 2 containing the tools will simultaneous bend the members in the plane of rota ion A (Figure 2) and twist the assembly by cooperation between opposing conical surfaces 78,80. The assembly of members is thus twisted through an angle defined by the chosen angle θ. The bent members can be released by separating tool 74,76 in the general manner described in relation to Figures 1 and 2. If required, the alonge members can be clamped in such plane adjacent the side of the bending device from which the bend to be formed by tool 74,76 is to extend, such that twisting occurs substantially only in, or at that side of, the composite bend.! Figure 9 shows an arrangement similar to that of Figur 8. However, tools 74,76 are modified in the manner shown in Figure 7 to enable a conical bend to be provided in an assembly of elongate members which includes lesser diameter members 73 and at least one larger diameter member 75. As shown, each of conical surfaces 78,80 is of lesser axial extent than the arrangement of Figure 8 by an amount sufficient to receive only members 73; with the body portion of tool 74,76 having a shoulder 88,90 for contacting and constraining member 75. Again, member 75 can be radially innermost or outermost in the bend formed, depending on which of tool 74,76 is mounted on pin 22 and arm 20. With reference ' to Figures 10 to 14, the device 120 has a central shaft 122 which extends through lower form tool 124 and upper form tool 126. The latter includes a disc 128 movable on shaft 122 relative to tool 124 between the position shown in which disc 128 and tool 124 define a cavity 130, and a raised position. Tool 126 also includes a disc 132, movable toward and away from disc 128. Shaft 122 may be secured to tool 124, with discs 128 and 132 movable along the shaft; or disc 132 may be secured to shaft 122 and movable therewith relative to tool 124 and disc 128. Each of tool 124 and disc 128 has a family of parallel slots 134,136 extending angularly with respect to shaft 122. Each slot in one family overlies a respective slot in the other family and >, in the arrangement illustrated, the slots of each family are concentric with the axis of shaft 122. Tool 126 also includes a family of spacer plates 138. The latter also are parallel and curved concentrically.with respect to corresponding to that of a res.pective one of slots 134 and slots 136. The arrangement is such that with tool 124 and disc 128 adjacent and disc 132 raised, as shown in Figure 10, each plate extends into a respective slot 136 but not substantially below the latter. However, as disc 132 is lowered, plates 138 are mov so as to pass through cavity 130 and into, and through, slots 134. As a consequence, cavity 130 is divided into a family of parallel channels 140 which also are concentric with shaft 122. As shown in Figures 12 to 14, each spacer plate 138 has an edge 142 which leads in such movement with lowering of disc 132 and which is inclined helically with respect to shaft 122. The inclination is such that leading edges extend away from the upper surface of tool 124 in an an i-clockwise direction as viewed in Figure 11. As plates 138 are moved with lowering of disc 132, the leading edges ride on complementary guide surfaces 135 and 137 (Figure 12) formed at the anti-clockwise end of slots 134 and 136, respectively. That movement is shown by arrow C in Figure 12 but, due to the guiding action of surfaces 135, 137, spacer plates 138 are also constrained to move clock¬ wise around slots 134,136 as indicated by arrow D; the overall movement being as shown by arrow E. Spacer plates 138 have vertical side edge 144,146 between which leading edge 142 extends. Because of the inclination of edge 142 edge 144, which is foremost in the clock-wise movement shown by arrow D, meets edge 142 at an acute angled corner (shown as truncated) , while edges 142,146 meet at an obtuse angle. With lowering of disc 132, the circumferential extent of plates 138 dividing cavity 130 into channels 140 increases, with corresponding increase in the length of channels 140. In use of the device of Figures 10 to 14, disc 132 is raised and disc moved upwardly from tool 124 to open cavity 130. A plurality of pipes P to be bent then are placed in parallel spaced relation on tool 124 so as to extend transversely with respect to shaft 122. Each of pipes P is located intermediate the ends of successive -slots 134, e::cept for the innermost pipe which is offset from the end of the innermost slot 134 against shaft 122. Beyond the ends of slots 134, disc 124 has a raised surface in which is formed a parallel series of grooves 145 in which the pipes are positioned in the parallel spaced relation illustrated. » 5 The grooves serve not only to position the pipes but also to secure them during bending. Disc 128 then is lowered to clamp pipes P in that relationship, after which disc 132 is lowered to pass plates 138 through cavity 130 and slots 134; each plate 138 passing 10 between successive pipes P, apart from the outermost plate 138 which simply passes by the outermost pipe. As indicated above, guidance of leading edge 142 of each plate 138 causes the latter also to move clockwise in slots 134,136. As a consequence, each edge 144 is caused to engage and move alo 15 a . respective pipe P located radially inwardly against each plate 138 so that the pipe conforms to the inner curvature of the plate and the channel 140 in which it is located as a result. By this action, all pipes are bent as an assembly; the bend extending clockwise (as viewed in Figure 10) , around 20 slo s 134,136 from the ends of the latter at which surfaces 135,137 are located. As seen most clearly in Figure 10, the pipes P illustrated are of different sections, the smaller intermediate pipes being clamped by provision of pressure pads 147 on the 25 under surface of disc 128. By this means, pipes of a variety of different sections can be accommodated. In Figures 15 to 17, there is illustrated a modified form of the device of Figures 10 to 14. In this modified form, the parts described in relation to the latter 30 Figures are shown for simplicity of illustration in broken outline, but with the same reference numerals being used. As shown in Figures 15 to 17, the device further includes a guide block 160 located below tool 124. Block 160 has a boss 162 at one end, in which is received an extension of shaft 122 below tool 124. Block 160 thus is rotatable against the undersurface of tool 124. At its end remote from boss 162, block 160 has a guide head 164 which projects upwardly across the periphery of topi 124 at least to the lower peripheral edge of disc 128. 164 has a flat upper surface in which is formed a plurality of parallel grooves 166 each-of which is. alignable with a respective one of grooves 145. As seen most clearly in Figure 15, block 160 is 5 fixed in relation to plates 138. This is effected by means of a bar 168 extending between guide head 164 and disc 132 and extending parallel to-shaft 122; the bar being secured to disc 132 and slidable through head 164, or vice versa. The arrangeme is such that, as disc 132 is lowered, it is caused to rotate on shaft 122 " by edge 142 of each plate 138 riding on guide surfaces 135; with bar 168 causing block 160 to rotate with disc 132. As a consequence of this rotation of block 160 and location of each pipe P in a respective ^ groove 166 and also in a respective groove 145 of tool 124, the extent of each pipe P beyond the bend being formed is drawn around tool 124 and disc 128 with guide head 164; this drawing function facilitates the bending operation resulting from engagement of each edge 144 with a respective pipe P. In use of the device of Figures 10 to 14', as. well as that of Figures 15-to 17, the pipes P are held against relative lateral movement by their location in grooves 145. In the case of the device of Figures 10 to 14, it is important for most efficient bending if the pipes also are held against longitudina movement, i.e. relative to each other or to tool 124. If a sufficient clamping force is not achieved between tool 124 and disc 128 to prevent longitudinal movement, -the pipes P may be clamped by any suitable means located toward their ends away fro which the bend is to be formed, such as by means of a clamp acting across grooves 145. In the device of Figures 15 to 17, rotation of block 160 results in grooves 166 tending to move longitudinally of pipes P in advance of the bend being formed. However, in this case, it is found that most efficient bending is achieved if pipes P are clamped in grooves 166 by suitable means so as to overcome that tendency, and to permit controlled limited movement of the pipes longitudinally in grooves 145, relative to tool 124. That movement of pipes P relative to disc 124 is by a drawing action resulting from rotation of block 160. ,-i. With reference to Fiσures 18 and 19, Darts similar to those of the device of Figures 10 to 14 are identified by the same reference numerals. In this case, the direction of inclination of leading, edges 142 of plates 138 is reversed, while the anti-clockwise end of slots ' 134,136 (as viewed in Figure 10} is provided with vertical surfaces down which • 5 side 144 rides. There consequently is no resultant movement of plates 138 clockwise around slots 134,136 as disc 132 is lowered; plates 138 moving vertically as shown by arrow D. In the arrangement of Figures 18 and 19, the pipes are arranged and gripped as- described in relation to Figures 10 10 to 14. However, as disc 128 is lowered, it is leading edge 142 of each plate which engages and moves along a respective .pipe with increasing angular extent of plates 138 received in cavity 130. Again, the plurality of pipes is bent as an assembly, with the bend again extending from the anti-clockwise 15 end of slots 134,136 around the slots. Edge 142 in the arrangement of Figures 18 and 19, and side edge 144 in the arrangement of Figures 10 to 14, can be shaped to avoid plates 138 biting into pipes P, thereby easing movement along the pipes. This is shown in 20 relation to edges 144 in Figure 11, where surfaces 152 indicate the. inner concave surfaces of plates 138 being turned outwardly away from slots 134 in the direction of pipes P in advance of the bend. The device of Figures 18 and 19 can, if required, be 25 provided with a guide block 160 as shown in Figures 15 to 17. In such case, provision most conveniently is made for the pipes P to be able to move longitudinally to a limited extent with rotation of the block. However, in contrast to the arrangement of Figures 10 to 14, disc 132 and plates 138 of the device of 30 Figures 18 and 19 do not rotate relative to shaft 122 during a bending operation. As a consequence, block 160 and disc can not be inter-connected by means of a bar 168 in the manner described in Figures 15 to 17, and an alternative arrangement is necessary to achieve rotation of the guide block in unison wit 5 the movement of edge 142 of each plate 138 along a respective one of pipes P during bending of the latter. A number of arrangement can be used, but a convenient one is to provide on guide head 164 of block 160 a portion having an inclined guide surface co-operable with edge 142 of the radially outermost plate 138 so ϋlϊl the guide surface rides along that edge, and the block rotated during a bending operation, in- a manner that is a converse of the relationship in Figures 10 to 14 between each edge 142 and guide surfaces 135,137. In each of the devices of Figures 10 to 14, Figures 15 to 17 and Figures 18 and 19, a bending operation can be performed using any convenient power source to lower disc 132 relative to discs 124,128. Thus, with disc 124 resting on a support surface, disc 132 can be driven down under the action of an electric motor or a pneumatic or hydraulic actuator. Alternatively, shaft 122 itself may be an extendable and retractable rod of such actuator, such as an hydraulic ram. The elongate members able to be satisfactorily bent in accordance with the invention can be of any suitable rigid material having , sufficient plasticity at the operating temperature. In the case of tubular members, these can incorporate a variety of core and/or coating materials since the bending operation gives rise to only slight sectional deformation, of members of rigid material of the necessary plasticity. Also, it is not necessary that the working surfaces of the principal forming- tool or of the secondary forming tool be harder than the material of the elongate members. Each one of a plurality of bending devices can be located such that a required sequence of bends along the elongate members can be formed. In such case, the bending devices may be spaced and mutually oriented such that, by sequential operation of each, the elongated members are bent as an assembly in the manner required to conform to a specific two- or three-dimensional surface, such as a support surface on which the bent assembly of members is to be mounted. While in the foregoing, description largely is directed to elongate members of substantially circular section, it is to be appreciated that members of other sections can be used. In particular, members of elliptical, square, hexagonal or any other section shapes capable of being assembled in a calculatable or regular fashion, can be bent in accordance with the invention. In relation to members of circular or moderate elliptical section, the precision bending possible is such that, not only are adjacent members in close conformity, but substantially no sectional deformation occurs. However, with tubular elongate members having surfaces which are flat, or an approximation thereto, some sectional deformation can occur even though precision of conformity is obtained. Thus, for an in plane bend formed in a plurality of square section tubular members arranged with a side face of each parallel and in contact with a side face of an adjacent such member, some notching of those faces is possible. However, this notching can be of benefit in serving to secure the members in assembly, when bent, by the notching giving rise to inter-locking of successive members. Finally, it is to be understood that various alterations, modifications ' and/or additions may be introduced into the constructions and arrangements of parts previously described without departing from the spirit or ambit of the invention.

Claims: Claims : - ^ 1. A method of bending a plurality of pipes or like elon¬ gate-members to conform to a common path as an assembly, wherein the unbent pipes are arranged in side by side relation with one another to form an assembly or group with the region of said group to be bent located within a cavity formed between two co- acting form-tools such that the cross-section of the cavity conforms closely to the periphery of the group of pipes, the group is gripped on the work side of the cavity to prevent relative lateral movement of the pipes with respect to one another during bending, and one of the form-tools is moved- relative to the other and along the pipes toward the stock end thereof to force the pipes to bend as an assembly so that the assembly conforms to the contour of the other form-tool, the individual pipes being free to move or adjust longitudinally with respect to one another at least at said region. 2. A method of bending pipes or like elongate members, wherein a plurality of the members is arranged in substantially parallel relation with one another to form an assembly with a region of said assembly at which a bend is to be formed being located in a .cavity formed between two co-acting form-tools, the cavity conforming closely to the periphery of the assembly and constraining the pipes substantially against relative lateral movement; and one of the form-tools is moved relative to the other and along said region toward one end of the assembly to bend the pipes progressively in the assembly to conform the region to the contour of the other form-tool while allowing relative longitudinal adjustment of the pipes over the length thereof between said form-tools. 3. A method according to claim 1 or claim 2, wherein said cavity is defined by a groove extending inwardly of and around a curved peripheral surface of the other form-tool and a side face of the one form-tool, the pipes and tools being positioned so that the periphery at said region of the assembly is engaged between opposed walls of said groove and between the base of said groove and said side face, with said end of the pipes being spaced beyond the tools, the one tool being movable to draw said side face around the groove and bend the pipes as an assembly. o conform, to the contour of said groove. 4. A method according to claim 3, wherein said other tool has two parts separable on a plane substantially parallel to sai groove,* said parts being moved together to bring said opposed walls into engagement with said pipes, the pipes being arranged in at least one layer in which the pipes are substantially in a common plane parallel to the plane on which said parts are separable, and movement of the one tool relative to the other tool bending the pipes as an assembly parallelto said separable plane. 5. A method according to claim 4, wherein said parts are moved to engage said pipes in a single said layer, at least one of said opposed walls being stepped, pipes of different section being engaged by said opposed walls. 6. A method according to claim 1 or 2, wherein said form- tools each comprises a roller, said cavity being defined by a respective curved peripheral surface of each tool and by a respective radial flange of each tool, the pipes and tools being positioned so that the periphery of said region of the assembly is engaged between said respective surfaces and between said respective flanges, with said end of the pipes being spaced beyond the tools, the one tool being moved around the other tool with the axes of the tools parallel and bending the pipes a an asembly to conform to. the contour of the respective surface of the other tool. 7. A method according to claim 6, wherein the pipes are arranged in at least one layer in which the pipes are substan¬ tially in a common plane extending between said flanges, movement of the one tool relative to the other tool bending the pipes as an assembly out of said plane- 8. A method according to any one of claims 1 to 7, wherein said pipes are arranged in side-by-side contact and bent as an assembly in such contact. 9. A method according to any one of claims 1 to 7, wherein spacer means is provided between adjacent ones of at least some of the pip'es, said spacer means being bent with said pipes. 10. A method according to claim 1 or claim 2, wherein said co acting tool comprises respective overlapping discs mounted for the pipes spaced beyond the tools, each disc having a family of curved slots therein with each slot- of one family overlapping a respective slot of the other family, the one tool having associated therewith a parallel family of spacer plates of complementary curvature to said slots and movable so that each passes through a respective slot of the one tool, through the cavity and through a respective slot of the other tool to divide the cavity into a family of curved channels, the pipes being arranged in parallel spaced relation between said tools and gripped thereby in said cavity such that each pipe in said cavity is off-set from said slots, and wherein the spacer plates are moved as a unit through said slots and cavity so that an edge of each engages and. moves along a respective pipe toward said end thereof and bend the pipe to conform to the contour of the.respective spacer plate and of a respective channel. 11. A method according to claim 10, wherein each spacer plate has a leading edge in such movement which extends helicall with respect to the direction of movement of the plates, the leading edges being moved on complementary guide surfaces to provide in such movement a component around the slots so that engagement of each plate with a respective pipe to bend the latter is by means of a side edge of the plate. 12. A method according to claim 10, wherein each spacer plate has a leading edge in such movement which extends helically with respect to the direction of movement of the plates, the plates being moved perpendicular of the discs so that the extent of each plate in the direction of the slots progressively increases and so that engagement of each plate with a respective pipe to bend the latter is by means of the leading edge. 13. A method according to claim 11 or 12, wherein said other form tool has a guide head associated therewith, and movable around the periphery thereof, said elongate members prio to bending, being arranged in said side by side relation such that on the work side of said cavity each elongate member is located in a respective one of parallel grooves formed in said other tool and on the stock side of said cavity each elongate member is located in a respective one of parallel groov " formed in said guide head; said guide head being moved around the periphery of said other form tool in the direction bending of said elongate members, in unison with said bending, to thereby effect a limited longitudinal drawing action on • 5 said elongate members. 14. Apparatus for bending pipes or like elongate members, having two co-acting form-tools mounted on support means so tha one of the tools is movable relative to the support means; the form-tools forming therebetween a cavity through which a 10 plurality of pipes can extend in side by side relation with one another so as to form an assembly such that the cross section of the cavity conforms closely to the periphery of the assembly; the form-tools being so movable that with a region of the assembly to be bent located in the cavity and the 15 assembly gripped to prevent relative lateral movement between the pipes with respect to one another, the one form-tool is movable relative to the other form-tool and along the pipes towards one end thereof to force the pipes to bend as an assembly so that the assembly conforms to the contour of the other form-tool. 15. Apparatus according to claim 14, wherein the cavity is defined by a groove extending inwardly of ardaround a curved peripheral surface of the other form-tool and a side face of the one form-tool with the one tool being mounted movement relative to the other tool so that said side face is able to ride around said peripheral surface, the groove having opposed walls adapted to engage the periphery of the assembly there¬ between and the base of the groove and said side face being adapte to engage the periphery of the assembly therebetween. 16. Apparatus according to claim 15, wherein said other tool has two parts .separable on a plane substantially parallel to said groove, said parts being movable to bring said opposed walls into engagement with said pipes at the periphery of said assembly. 17. Apparatus according to claim 15 or 16, wherein said other tool is a roller, said groove extending around the cir¬ cumference thereof, said groove being stepped to provide radially inner and outer portions of said groove each of which has a respective spacing between said opposed walls so that pipes of respective sections can be engaged between said opposed walls. 18. Apparatus according to claim 14, wherein each tool comprises a roller, said cavity being defined by a respective curved peripheral surface of each tool " and by a respective radial flange of each tool, the tools being positioned so that respective surfaces are radially spaced and the one tool is movable around the other tool with the axes of the tools parallel acid the flanges axially spaced. 19. Apparatus according to claim 14, wherein said co-acting tools comprises respective overlapping discs mounted for movement toward each other to define said cavity therebetween, and away from each other, each disc having a family of parallel overlapping a respective slot of the other family, the.one tool having associated therewith a family of parallel spacer plates -of complementary curvature to said slots and movable perpendicularly of said discs between a retracted position and an operative position, each plate in movement to its operative position passing through a respective slot of the one tool, through the cavity and a respective slot of the other tool to divide the cavity into a family of curved channels, the arrangement being such that with a plurality of pipes gripped in said cavity in parallel relation with each pipe being off¬ set from the slots in said cavity and having said end thereof beyond the tools, the spacer plates can be moved as a unit to their operative position to divide the cavity into said channels such that during movement to that position an edge of each spacer plate engages and moves along a respective pipe towards said end of the latter and bend the pipe to conform to the contour of the respective spacer plate and of a respective channel. 20. Apparatus according to claim 19, wherein each spacer. plate has a leading edge in movement toward its operative position which edge extends helically with respect to the direction of that movement of the plates, at least one slot of at least one of said families thereof defining a guide surface engaged by the leading edge of the respective spacer plate such that during movement of the plates to the operative position a component of movement around the slots is imparted to the plates as a unit so that each plate is adapted to engage with and bend a respective pipe by means of a side edge of the plate. 21. Apparatus according to claim 19, wherein each spacer plate has a leading edge in movement toward its operative position which edge extends helically with respect to the direction of that movement, the movement being perpendicular with respect to the discs and the inclination of the edges with respect to the discs being such that the extent of each plate in the direction of the slot progressively increases so that the leading edge of each plate is adapted to engage and bend a respective pipe. " 22. Apparatus according to claim 20 or 21, wherein said other tool has a guide head associated therewith and movable around the periphery thereof, said other tool having a set of parallel grooves formed in a surface thereof facing said one tool and said guide head having a set of parallel grooves formed therein, said sets of grooves being such that each groove of one set can be aligned with a respective groove of the other set with ' said cavity therebetween to enable each of said elongate members when in said side by side relation to be located in a respective groove of each set, said guide head being movable in the direction of bending in unison with said bending to thereby effect a limited drawing action on said elongate members. 23. Apparatus according to claim 22, wherein said guide head is'provided at one end of a guide member extending across a face of the one tool remote from the other tool, the guide member having a boss at its other end by which it is rotatable on said shaft for movement of the guide head around the periphery of the other tool; the boss being rotatable in unison with the spacer plates during a bending operation to move the one end of the elongate members in the direction of bending. 24. Apparatus according to claim 23, including a carrier disc for said spacer plates, said carrier disc being movable on said shaft and connected to said guide block to rotate the latter during movement of said spacer plates. 25. Apparatus according to claim 23, wherein said guide head is engaged with the leading edge of an outermost said spacer plate so as to be rotated in response to movement of that spacer plate.

Inventors: JAMES ARTHUR GEORGE WILLIAM, JOHNSON RONALD CLYDE, PERROTT COLIN MAURICE
Applicants: COMMW SCIENT IND RES ORG, JAMES ARTHUR GEORGE WILLIAM, JOHNSON RONALD CLYDE, PERROTT COLIN MAURICE
Application year: 1982
Main classification: B21D7
IPC codes: B21D7