SHEET MATERIAL FORMING

Abstract

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

Claims

1-43. (canceled)

44. A metal sheet material having a first major surface and a second major surface, the metal sheet material comprising a pattern of projections and depressions formed on both major surfaces and on or in a first portion or region of the metal sheet material and indicia formed on or in a second portion or region of the metal sheet material at an interruption in the pattern of projections and depressions, wherein the indicia has a form and the form of the indicia is usable to provide an indication of an alignment of tools used to form the pattern of projections and depressions.

45. A metal sheet material according to claim 44, wherein the second portion or region is surrounded by the first portion or region.

46. A metal sheet material according to claim 44, wherein one or more or each projection formed on one or each major surface of the metal sheet material corresponds to a depression on the other major surface thereof.

47. A metal sheet material according to claim 44, wherein the indicia is formed on a flat surface of the metal sheet material.

48. A metal sheet material according to claim 47, wherein the indicia protrude out of the plane of the sheet material.

49. A metal sheet material according to claim 44, wherein the indicia protrude out of the plane of the sheet material.

50. A metal sheet material according to claim 44, wherein a degree of distortion of the form of the indicia corresponds to a degree of misalignment of the tools.

51. A metal sheet material according to claim 50, wherein at least a portion of the indicia provides a machine-readable indication of the alignment of tools used to form the metal sheet material and wherein the degree of distortion of the indicia corresponds to the degree of misalignment of the tools.

52. A metal sheet material according to claim 44, wherein the pattern of projections and depressions are arranged in an array.

53. A metal sheet material according to claim 44, wherein the pattern of projections and depressions comprises a plurality of rows and/or columns.

54. A metal sheet material according to claim 53, wherein the pattern of projections and depressions is configured and distributed such that lines drawn on a surface of the metal sheet material between adjacent rows of projections and depressions are not rectilinear.

55. A profile or beam or article having a shaped cross-section and comprising a metal sheet material according to claim 44.

56. A pair of forming rolls for forming metal sheet material therebetween, each of the forming rolls comprising a respective first forming surface and a respective second forming surface at an interruption in the first forming surface, wherein the first forming surfaces cooperate, in use, to form a pattern of projections and depressions on both major surfaces in or on a sheet metal material formed therebetween while simultaneously the second forming surfaces cooperate to form indicia at an interruption in the pattern of projections and depressions, wherein the indicia are distorted if the rolls are misaligned, wherein one of the second forming surfaces comprises a male forming surface and the other of the second forming surfaces comprises a corresponding female forming surface.

57. A pair of forming rolls according to claim 56, wherein the second forming surface of one roll is recessed with respect to the first forming surface of said one roll.

58. A pair of forming rolls according to claim 56, wherein one of the forming rolls comprises an insert comprising the second forming surface of said forming roll, for example wherein the insert is removably received or receivable within a recess of said forming roll, for example wherein the insert is secured or securable to its forming roll by a locking means and wherein the other of the forming rolls may comprise an insert comprising the second forming surface of said forming tool, for example wherein the insert is removably received or receivable within a recess of said forming roll, for example wherein the insert is secured or securable to its forming roll by a locking means.

59. A pair of forming rolls according to claim 58, wherein the locking means comprises a locking projection that engages with a locking recess, for example wherein the locking projection is movable between a deployed or locked position or condition and an undeployed or retracted or unlocked position or condition, for example wherein the locking projection is resiliently biased toward the deployed or locked position or condition.

60. A pair of forming rolls according to claim 56, wherein each forming roll comprises a driver located at or toward a first end thereof, the other end of each forming roll being free of the driver.

61. An apparatus for forming metal sheet material, the apparatus comprising a pair of forming rolls according to claim 56 movably mounted relative to one another

62. An apparatus according to claim 61, wherein the first forming surfaces comprise a plurality of projections or teeth, the geometry and position of the projections or teeth and the spacing between the forming rolls being such that the projections or teeth on one forming roll register and/or extend, in use, into gaps between the projections or teeth on the other forming roll.

63. An apparatus according to claim 61, wherein separation of the forming rolls is dimensioned such that, in use, metal sheet material is cold work hardened between the first forming surfaces and wherein the second forming surfaces are configured to cooperate, in use, to emboss indicia in or on sheet metal material therebetween.

Description

[0095] Embodiments of the invention will now be described by way of example only with reference to the accompanying drawings in which:

[0096] FIG. 1 is an end view of a forming tool according to one embodiment of the invention;

[0097] FIG. 2 is a perspective view of a segment of the forming drum of the forming tool of FIG. 1;

[0098] FIG. 3 is a section view along line A-A of FIG. 1;

[0099] FIG. 4 is a plan view of the radial hole in the tool of FIG. 1;

[0100] FIG. 5 is a perspective view of the marking insert for incorporation into the forming tool of FIGS. 1 to 3;

[0101] FIG. 6 is a side view of the marking insert of FIG. 4;

[0102] FIG. 7 is a section view along line B-B of FIG. 5;

[0103] FIG. 8 is a side view of a forming tool for cooperation with the tool of FIG. 1;

[0104] FIG. 9 is an exploded view of the forming tool of FIG. 1 illustrating an exemplary driving assembly in more detail;

[0105] FIG. 10 is a perspective view of a first end of the tool of FIGS. 1 and 9;

[0106] FIG. 11 is a perspective view of a second end of the tool of FIGS. 1 and 9;

[0107] FIG. 12 is a perspective view of an aligned pair of tools according to an embodiment of the invention; and

[0108] FIG. 13 is a top view of a sheet material according to an embodiment of the invention.

[0109] 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.

[0110] 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.

[0111] 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, 28 for receiving a portion of a respective one of the first and second end parts 3, 4.

[0112] 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.

[0113] 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.

[0114] 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.

[0115] 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.

[0116] 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.

[0117] 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.

[0118] 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.

[0119] 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.

[0120] 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.

[0121] 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.

[0122] 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.

[0123] 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 8 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).

[0124] 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.

[0125] 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, 278, 27C for receiving an end of respective datum keys 28A, 288, 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.

[0126] 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. 288, 28C partly received in the interruptions 45.

[0127] 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).

[0128] In order to fabricate a set of tools 1, 8 according to the invention, the following process is followed.

[0129] 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.

[0130] 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, on both the gear (e.g. the spur gear 4 of the first tool 1) and in the pinion DA, (e.g. the spur gear 4 of the second tool 8).

[0131] 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.

[0132] Moreover, once the desired patterning process has been established, the spur gear form is calculated according to equations (1) to (3):—

[00004]$d_{\mathrm{TP}}=162\mathrm{mm}$

[0133] In one exemplary embodiment, the sheet material to be rolled is 0.6 mm thick (i.e. g=0.6 mm) steel.

[0134] In this instance, the spur gear 4 has the following characteristics, (setting k=0.1 and d.sub.TP:d.sub.O=1):

[00005]$\begin{array}{c}\mathrm{DPCD}=162-\left(0.6+0.1\right)\\ =161.3\mathrm{mm}\end{array}$$N=80$$P=0.5$$\mathrm{Addendum}\left(A\right)=2$$\mathrm{Dedendum}\left(D\right)=2.3$$\mathrm{Tooth}\mathrm{thickness}\left(T\right)=3.14$$\mathrm{Pressure}\mathrm{angle}={20}^{°}$

[0135] 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.

[0136] 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.

[0137] 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.

[0138] 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.

[0139] 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.

[0140] 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.