SHEET MATERIAL FORMING

Abstract

A formed sheet metal material (100) and methods, tools (1, 2, 8) and apparatus for forming the sheet metal material (100) in which a pattern of projections and depressions are cold worked in a first portion (101) and, simultaneously, indicia (103) is embossed in a second portion (102) of the sheet material (100). The cold worked portion (101) is formed with the projections and depression configured and distributed such that lines drawn on a surface of the formed sheet material (100) between adjacent rows of projections and depressions are not rectilinear. The indicia (103) is indicative of the alignment between the tools (1, 2, 8).

Claims

1-43. (canceled)

44. A method of forming a sheet metal material, the method comprising the steps of locating a sheet material between a pair of tools and moving the tools such that the tools form simultaneously a pattern of projections on both major surfaces of the sheet material by cold working in a first portion of the sheet metal material and indicia by embossing in a second portion of the sheet metal material at an interruption in the pattern of projections, wherein the form of the indicia is indicative of the alignment between the tools.

45. A method according to claim 44, wherein the forming of the pattern comprises forming projections distributed such that lines drawn on a surface of the formed sheet material between adjacent rows of projections and depressions are not rectilinear.

46. A method according to claim 44, comprising moving the tools such that one or more forming portions of one of the tools forces or compresses the sheet material against the other tool, thereby embossing the sheet material to form the indicia therein or thereon.

47. A method according to claim 44, wherein the second portion is surrounded or bound by the first portion.

48. A cold forming tool for cold forming a sheet material according to the method of claim 44, the forming tool comprising a first forming surface configured to form, in use, a pattern of projections in a first portion of a sheet metal material and a second forming surface configured to form indicia in a second portion of the sheet metal material that is at an interruption in the pattern of projections, where the second forming surface is recessed with respect to at least a portion of the first forming surface.

49. A tool according to claim 48, wherein the tool comprises a substrate including the first forming surface and an insert removably received within a recess of the substrate, which insert includes the second forming surface and wherein the insert is secured or securable within the recess by a lock.

50. A tool according to claim 48, wherein the second forming surface is configured to form, in use, in a sheet metal material indicia that provides a visual indication of the alignment between the tool and another tool with which the tool cooperates.

51. A tool according to claim 48, wherein the second forming surface is configured to form, in use, in a sheet metal material indicia that is distorted if the tool is misaligned with another tool with which the tool cooperates.

52. A tool according to claim 48, wherein the pattern comprises an array of projections and the indicia comprises an identifier.

53. A pair of cold forming tools for cold forming sheet metal material therebetween, the pair of tools comprising a first forming tool according to claim 44 and a second forming tool, the second forming tool comprising a first forming surface for cooperating with the first forming surface of the first tool to form a pattern in or on a sheet metal material formed therebetween and a featureless surface for cooperating with the second forming surface of the first forming tool to form indicia on a sheet metal material formed therebetween.

54. A pair of forming tools according to claim 53, wherein the first forming surfaces of the forming tools are configured to cooperate, in use, to cold work a sheet metal material therebetween and the second forming surfaces of the forming tools are configured to cooperate to emboss the sheet metal material therebetween.

55. A pair of forming tools for forming sheet metal material therebetween, each of the forming tools comprising a respective first forming surface and a respective second forming surface, wherein the first forming surfaces cooperate, in use, to form a pattern of projections in or on a sheet metal material formed therebetween on both major surfaces of said sheet material by cold working while the second forming surfaces cooperate to form indicia by embossing at an interruption in the pattern of projections in or on a sheet metal material formed therebetween, the second forming surfaces being configured such that the indicia is distorted if the tools are misaligned.

56. A pair of tools according to claim 55, wherein the second surfaces comprise cooperating forming edges separated by a predetermined distance, in use, when a sheet metal material is formed between the tools when the tools are in proper alignment.

57. A pair of tools according to claim 55, wherein the first forming surfaces cooperate, in use, to form an array of projections and depressions distributed such that lines drawn on a surface of the formed sheet material between adjacent rows of projections and depressions are not rectilinear.

58. A pair of tools according to claim 55, wherein the second forming surface of each tool is surrounded or bound by the first forming surface thereof.

59. An apparatus for forming sheet metal material, the apparatus comprising a pair of opposed tools according to claim 55, movably mounted relative to one another, wherein the first forming surfaces comprise projections or teeth, the geometry and position of the projections or teeth and the spacing of the tools being such that the projections or teeth on one tool register and/or extend, in use, into gaps between the projections or teeth on the other tool.

60. A formed sheet metal material comprising a pattern of projections formed on or in a first portion or region thereof and indicia formed on or in a second portion or region thereof at an interruption in the pattern of projections, wherein the pattern comprises projections on both major surfaces of the sheet material and is formed by cold working, wherein the indicia are formed by embossing and are usable to provide an indication of the alignment of tools used to cold work the sheet material.

61. A formed sheet material according to claim 60, wherein the pattern is configured and/or distributed such that lines drawn on a surface of the formed sheet material between adjacent rows of projections and depressions are not rectilinear.

62. A formed sheet metal material according to claim 60, wherein at least a portion of the indicia provides a visual and/or machine readable indication of the alignment of tools used to form the sheet material.

63. A formed sheet metal material according to claim 60, wherein the second portion is bound by the first portion.

64. A profile or beam or article having a shaped cross-section, the profile or beam or article having a shaped cross-section comprising a sheet metal material according to claim 60.

Description

[0096] Embodiments of the invention will now be described by way of example only with reference to the accompanying drawings in which:

[0097] FIG. 1 is an end view of a forming tool according to one embodiment of the invention;

[0098] FIG. 2 is a perspective view of a segment of the forming drum of the forming tool of FIG. 1;

[0099] FIG. 3 is a section view along line A-A of FIG. 1;

[0100] FIG. 4 is a plan view of the radial hole in the tool of FIG. 1;

[0101] FIG. 5 is a perspective view of the marking insert for incorporation into the forming tool of FIGS. 1 to 3;

[0102] FIG. 6 is a side view of the marking insert of FIG. 4;

[0103] FIG. 7 is a section view along line B-B of FIG. 5;

[0104] FIG. 8 is a side view of a forming tool for cooperation with the tool of FIG. 1;

[0105] FIG. 9 is an exploded view of the forming tool of FIG. 1 illustrating an exemplary driving assembly in more detail;

[0106] FIG. 10 is a perspective view of a first end of the tool of FIGS. 1 and 9;

[0107] FIG. 11 is a perspective view of a second end of the tool of FIGS. 1 and 9;

[0108] FIG. 12 is a perspective view of an aligned pair of tools according to an embodiment of the invention; and

[0109] FIG. 13 is a top view of a sheet material according to an embodiment of the invention.

[0110] Referring now to FIGS. 1 to 4, there is shown a forming tool 1, which is a cylindrical roll former 1 in this embodiment, for cold roll forming a sheet material. The tool 1 includes a central forming drum 2, first and second end parts 3, 4, an insert 5, a pair of locating rings 6 and locking mechanism 7 for releasably securing the insert 5 within the forming drum 2.

[0111] The forming drum 2 is in the form of a hollow cylinder or roll that provides a substrate on which a first profiled forming surface 21 is incorporated on its outer circumferential surface. In this embodiment, the first profiled forming surface 21 incorporates a pattern of projections 21a arranged in an array having a plurality of rows and columns. The forming drum 2 includes at least one, and preferably a pair of, coaxial radial holes 22, 23 located preferably centrally along its longitudinal axis, the hole 22, 23 or each of which includes a counterbore 22a, 23a extending inwardly from the outer circumference of the forming drum 2. The counterbores 22a, 23a are substantially rectangular in plan with rounded corners, as shown more clearly in FIG. 4. The counterbore 23a of one of the radial holes 23 includes one rounded corner 20a having a larger diameter than the other rounded corners of the counterbore 23a. The holes 22, 23 and corresponding counterbores 22a, 23a need not be of the same dimensions. The holes 22, 23 and corresponding counterbores 22a, 23a need not be coaxial.

[0112] The forming drum 2 also includes eight longitudinal through holes 24 extending parallel to the axis of the forming drum 2 and spaced equally from and about the longitudinal axis. Each end of each longitudinal hole 24 is tapped with a female thread for cooperation with a respective threaded bolt 30, 40. Each axial end of the forming drum 2 includes a recess 25, 26 for receiving a portion of a respective one of the first and second end parts 3, 4.

[0113] The first end part 3 is in the form of a substantially cylindrical disc with a central hole 31, a radial flange 32 on a first side thereof and eight holes 34 extending through the thickness of a central portion of the disc with positions corresponding to those of the through holes 24 in the forming drum 2. Each of the through holes 34 includes a counterbore 34a on the first side of the first end part 3 for accommodating the head of a respective bolt 30. The second side of the first end part 3 is received within a first of the end recesses 25 of the forming drum 2 and secured thereto by eight bolts 30 extending through the through holes 34 of the first end part 3 and engaging the female threads in the through holes 24 of the forming drum 2 with one of the locating rings 6 captivated between the end of the forming drum 2 and the radial flange 32.

[0114] The second end part 4 is in the form of a hollow cylindrical spur gear member 4 with an axial hole 41 therethrough, a plurality of gear teeth 42 extending outwardly therefrom, a radial undercut providing a shoulder 43 on a first side thereof and eight through holes 44 with positions corresponding to those of the through holes 24 in the forming drum 2. Each of the through holes 44 includes a counterbore 44a on a second side of the second end part 4, opposite the first side, for accommodating the head of a respective bolt 40. The undercut, first side 43 of the second end part 4 is received within a second of the end recesses 26 of the forming drum 2 and secured thereto by eight bolts 40 extending through the through holes 44 of the second end part 4 and engaging the female threads in the through holes 24 of the forming drum 2 with the other locating ring 6 captivated between the gear teeth 42 of the second end part 4 and the end of the forming drum 2.

[0115] As shown more clearly in FIGS. 5 to 7, the insert 5 is in the form of a substantially rectangular block with rounded vertical corner edges 50, 50a to provide an upper forming face 51 that is substantially rectangular in plan with rounded edges. One of the corner edges 50a has a slightly larger radius than the others for cooperation with the rounded corner 20a of the counterbore 23a within which the insert 5 is to be received to ensure proper orientation.

[0116] The base surface of the forming face 51 of the insert 5 is curved to provide a constant depth recess in the circumference of the forming drum 2 when the insert 5 is received therein. The upper forming face 51 includes forming edges 52 that delineate a brand logo in this embodiment. The forming edges 52 delineate the outline of the letters of the logo with the letters themselves appearing as depressions 52a within the delineated outline or between the forming edges 52.

[0117] The insert 5 also includes on a first side thereof a locking recess 53 with a flat ledge 54 that is substantially parallel to the forming face 51 and a tapered surface 55 opposite the flat ledge 54 to provide a wide mouthed locking recess 53 that tapers to a narrow base 56 skewed toward the flat ledge 54. The insert 5 also includes a cutout 57 in a second side thereof, opposite the first side, and in the bottom of the insert 5. The cutout 57 is inclined, to provide a lead-in edge, in the same direction as the tapered surface 55 of the locking recess 53.

[0118] The locking mechanism 7 includes a locking pin 70 and a compression spring 71, both of which are captivated within one of the through holes 24 in the forming drum 2 between one of the bolts 40 and the locking recess 53 of the insert 5. As shown more clearly in FIG. 3, the insert 5 is received within the counterbore 23a of one of the radial holes 23 of the forming drum 2 with the locking recess 53 facing the second end part 4. The locking pin 70 has a first, rounded end that is received within the locking recess 53 and engages the tapered surface 55. The locking pin 70 is biased by the spring, which is compressed between the end of the bolt 40 and a second, flat end of the locking pin 70. The provision of a biased locking pin 70 that engages a tapered surface 55 provides retaining forces along both the axis of the insert 5 and the axis of the locking pin 70.

[0119] With the insert 5 received and retained with the counterbore 23a of the radial hole 23 of the forming drum 2, the forming face 51 is substantially contiguous with and adjacent the first profiled forming surface 21, albeit recessed slightly with respect thereto. Thus, as the tool 1 forms a sheet material, both the indicia and a portion of the pattern are formed simultaneously.

[0120] Turning now to FIG. 8, there is shown the forming drum 8 of a second tool, which is also in the form of a cylindrical roll former and is substantially similar to the forming drum 2 of the first tool 1, wherein like features are depicted with like reference numbers with the prefix 2 replaced with the number 8. The second tool assembly includes the forming drum 8, first and second end parts, 3, 4, locating rings 6 and a locking mechanism 7 assembled in a similar manner to that described above in relation to the first tool 1. The radial hole 83 is adapted to receive an insert (not shown), which may be a blank having a featureless forming surface for cooperating with the forming edges 52 of the insert 5 of the first tool 1 to mark a sheet material with indicia.

[0121] Alternatively and in accordance with one aspect of the present invention, the insert (not shown) may include forming edges that cooperate with the forming edges 52 of the insert 5 to provide the indicia. For example, the forming edges of the further insert may comprise forming edges that are received by and/or register with the depressions 52a within the delineated outline or between the forming edges 52. It will be appreciated by those skilled in the art that with such an arrangement, any misalignment between the tools 1, 8 would be readily visible by a distortion of the logo.

[0122] In further preferred alternative embodiments, the forming edges 52 may delineate indicia which is or are configured to be machine readable, for example in the form of one or more bar codes and/or quick response (QR) codes. In such embodiments, even minor distortion resulting from a misalignment between the tools 1, 8 may be detected using computerised scanning and processing. In fact, it is envisaged that the indicia may be selected such that the nature of the misalignment may be discernable from the extent and nature of the distortion. The use of QR codes or similar types of indicia could form the basis of such an arrangement.

[0123] The tools 1, 8 are rotatably mounted within an apparatus (not shown) a predetermined distance apart and interconnected by their respective driving means (not shown), which drives the gear teeth 42 of the second end part 4 to ensure that they contra-rotate at the same speed. Rotation of the tools 1, 8 causes the array of projections 21a on the first tool 1 to register and extend into gaps between the projections (not shown) on the other tool 8.

[0124] In use, the tools 1, 8 cooperate to form a pattern of projections and depressions in a sheet material fed between them, while the locating rings 6 retain the sheet material between them. As the tools 1, 8 rotate, the projections 21a on one tool 1 urge portions of the sheet material into gaps between the projections (not shown) on the other tool 8, thereby defining an effective thickness or amplitude defined between the peaks of the projections on each side of the sheet material. In this embodiment, the material is sheet steel and the forming of the pattern of projections and depressions results in plastic strain hardening of the sheet material, having been formed by deforming the sheet material locally, as explained in more detail in WO2009/063154 (and/or one of GB2450765A and EP0891234A).

[0125] In addition, as the tools 1, 8 form the pattern of projections and depressions in the sheet material, the forming edges 52 of the insert 5 bear against the blank (not shown) in the other tool 8 to emboss the indicia on the sheet material. Alternatively, where the insert (not shown) in the other tool includes further forming edges, these may cooperate with the forming edges 52 of the insert 5 to emboss or otherwise form the indicia.

[0126] Turning now to FIGS. 9 to 12, each of the recesses 25, 26 (only one of which is shown) of the forming drum 2 is circular in plan and bound by an annular wall 26A. Equi-spaced about the recess 26 and inboard of the annular wall 26A, are a series of rebates 27A, 27B, 27C for receiving an end of respective datum keys 28A, 28B, 28C. The shoulder 43 of the spur gear member 4 includes three interruptions 45 (only one of which is shown) which are complementarily shaped to receive the other end of the datum keys 28A, 28B, 28C.

[0127] When engaged, the interrupted shoulder 43 extends through the locating ring 6 and lies against the circular recess 26 and is bounded by the annular wall 26A with the datum keys 28A, 28B, 28C partly received in the interruptions 45.

[0128] The central hole 31 of the first end part 3 includes a keyway 31A and the central hole 41 of the spur gear member 4 includes a corresponding keyway 41A aligned with the keyway 31A of the first end part 3 when the tool 1 is in an assembled condition, thereby to receive a keyed driving shaft (not shown).

[0129] In order to fabricate a set of tools 1, 8 according to the invention, the following process is followed.

[0130] Firstly, it is determined what sort of patterned and corresponding patterning process is required. The type of tooth form, the height of the tooth, inter-tooth pitch (in rows and columns) are all important characteristics to be considered when seeking to manufacture a particular patterned sheet material. Thus, once the tooth form is determined, a blank roll 2 is provided. One of the recesses (e.g. 26) is used to determine a roll datum position DP. The tooth form is then provided on the outer periphery 21 of the forming drum 2, for example, by one or more of cutting, milling, grinding, etching and so on, but using the datum position DP to determine the starting position for the forming operation.

[0131] As shown is FIG. 12, the spur gear 4 is also aligned to the datum position DP to provide a gear datum alignment position DA.sub.G on both the gear (e.g. the spur gear 4 of the first tool 1) and in the pinion DA.sub.p (e.g. the spur gear 4 of the second tool 8).

[0132] In this way it is clear that the pattern formed on the rolls 1, 8 and the position of the spur gears 4 are aligned to a single defined point on each roll 1, 8.

[0133] Moreover, once the desired patterning process has been established, the spur gear form is calculated according to equations (1) to (3):— [0134] d.sub.TP=162 mm

[0135] In one exemplary embodiment, the sheet material to be rolled is 0.6 mm thick (i.e. g=0.6 mm) steel.

[0136] In this instance, the spur gear 4 has the following characteristics, (setting k=0.1 and d.sub.TP:d.sub.0=1); [0137] DPCD=162−(0.6+0.1) [0138] =161.3 mm [0139] N=80 [0140] P=0.5 [0141] Addendum (A)=2 [0142] Dedendum (D)=2.3 [0143] Tooth thickness (T)=3.14 [0144] Pressure angle=20°

[0145] The shaft (not shown) extending through the first tool 1 is driven by a motor at a first ‘jog’ speed which causes rotation of that tool 1 and, through the action of the intermeshing spur gears 4, caused contra-rotation of the other roll 8.

[0146] With the rolls 1, 8 being driven at a first speed, the sheet material is fed through the nip and onto the subsequent forming rollers. Once the material is fed through all of the stations, the rolls 1, 8 are driven at their faster running speed and the process of manufacturing commences.

[0147] It is of note that once the material to be patterned passes into the nip, the rolls 1, 8 are separated slightly, thereby causing separation of the spur gears 4. This separation ensures that the teeth of the gears do not contact at the previous line of action and thus are not drivingly engaged. At this point, the rolls 1, 8 are driven by the action of the drive means direct to the shafts.

[0148] Referring now to FIG. 13, there is shown a sheet material 100 comprising a cold worked region 101 in which a pattern of projections is formed on both major surfaces, each projection having a corresponding depression on the opposite major surface. The pattern is formed such that lines drawn on a surface of the formed sheet material between adjacent rows of projections and depressions are not rectilinear. The sheet material 100 also includes a series of interruptions 102 in the cold worked pattern on which is formed indicia 103.

[0149] It will be appreciated by those skilled in the art that several variations to the aforementioned embodiments are envisaged without departing from the scope of the invention. For example, other sheet materials may be formed by the present invention, which may, but need not, comprise steel or metal or even plastics material. The forming edges 52 may be configured to delineate or define any indicia, such as alphanumeric indicia, one or more images or a unique identifier relating to the tool or a pair of tools or a forming machine or a manufacturer, e.g. a sheet forming manufacturer and/or tool manufacturer. Moreover, the locking mechanism 7 need not include a spring-biased locking pin 70, e.g. it may comprise any suitable locking arrangement such as a ball and detent arrangement or even a bayonet-type locking mechanism or any other type of locking mechanism or means. Several other variations will be appreciated from the disclosure herein or recognised readily by the skilled person.

[0150] It will also be appreciated by those skilled in the art that any number of combinations of the aforementioned features and/or those shown in the appended drawings provide clear advantages over the prior art and are therefore within the scope of the invention described herein.