STRIP SHAPING MECHANISM

Abstract: The application describes apparatus for concave shaping metal strip which passes the strip through a set of rolls at which appropriate concave shaping is applied to the strip by means of a shaping set of rolls; wherein the strip is supported in its passage through the roll set by means of a flexible supporting member, whereby to ensure that the strip is subject to the shaping process along the total passage thereof through the shaping set of rolls. The supporting member can be a belt or web, and can be continuous. The device is particularly useful for shaping reflective louvres for use in fluorescent lamp fittings.

Description: STRIP SHAPING MECHANISM This invention relates to strip shaping mechanism, and is especially applicable to shaping mechanisms associated with a processing machine such as a press stamping machine where the shaping mechanism processes a strip product in association with strip feeding and press stamping machinery with one or more stamping actions to produce any one of a range of a particular product from the shaped strip material. Thus, for example, such a strip shaping mechanism may well be used for the shaping of strip formed of light metal alloy in association with a press stamping machine where the light metal alloy strip is sequentially stopped and stamped at a number of stamping stations within the machine ready for further fabrication to constitute eventually reflective and separating louvres for lighting installations. Such louvres require in general a lower facing concave curved shaping transverse to the length thereof below which is disposed an elongate lighting source, and which is usually provided by passing the strip metal transversely to its length through a roll set of three or more rolls to provide the necessary curvature to ensure, in the final product, such a concave reflective surface above the elongate (typically fluorescent) lamp to reflect the light directed from the upper surface of the louvre down to the room or office space located therebelow, to maximise for any given light source the illumination of that office or room space. Amongst the problems associated with such apparatus for providing a concave curved surface to the strip intended for such overhead lamp louvres, is that, because of the very nature of a three roll system, for example, frequently used to provide such concave shaping, the lateral end areas of the louvres tend to end up planar because the rolls are unable to provide a concave surface to the end portion thereof, the rolls not being able to be subject lateral ends to the curve-creating force of the three rollers, by their very nature and disposition. It is an object of the present invention to overcome or at least substantially reduce the above mentioned problem. In accordance with one aspect of the invention there is provided apparatus for concave shaping metal strip including passing the strip through a set of rolls at which appropriate concave shaping is applied to the strip by means of a shaping set of rolls; wherein the strip is supported in its passage through the roll set by means of a flexible belt-like member, whereby to ensure that the strip is subject to the shaping process along the total passage thereof through the shaping set of rolls. In accordance with another aspect of the invention there is provided a method for concave shaping metal strip including passing the strip through a set of rolls at which the concave shape is applied to the strip wherein the strip is supported in its passage through the roller set by means of a flexible belt-like member, whereby to ensure that the strip is subject to the shaping process along the total passage thereof through the shaping set of rolls. The flexible belt-like member may be of a continuous nature. The roll set may comprise three rolls, two of the rolls being provided for horizontally aligned parallel rotation, and the third opposed and parallel to the other rolls, applied into the gap between the first and second rolls just above mentioned such that the passage of the strip together with its supporting member are subject to a deflection by the rolls and a concave forming motion. By means of the invention, a concave transverse configuration to the strip, such as to be of the required nature for a concave reflective lamp louvre is provided, the association of the supporting member with the strip ensuring that the appropriate shaping of the latter is fully accomplished in its passage through the roll set, since the supporting member prevents a flattening motion of the strip as it passes out of the roll system. The supporting member may comprise a belt or a web-like member. Bearing in mind that louvres to be formed from metal strip may be of a length of two metres or more, it will be appreciated that the web or belt, together with the associated apparatus for subjecting the strip to a concave configuration may be of very substantial width capable of accommodating such a length. The concavity provided by the roll set may, in accordance with appropriate optical requirements, be varied during the transport of the strip through the shaping set of rolls by ensuring that the roll applied between the two fixed rolls, can be varied between different sets of metal strips to be shaped, and indeed during the passage of a single strip therethrough. Thus, the configuring mid-roller may be capable of movement into and out of the gap between the two supporting rolls during the passage of a single strip to provide, if desired, a complex concave configuration appropriate for the final requirement with respect to the reflecting lamp louvre for which the strip is being prepared. In order that the invention may be more readily understood one embodiment thereof will now be described by way of reference to the accompanying drawings in which: Figure 1 is a schematic side elevation of strip shaping apparatus in accordance with the invention; Figure 2 is an enlarged schematic view of the overhead cam arrangement controlling the mind roll of the control set; and Figure 3 shows in an enlarged view the controlling roll and its adjustability. Referring to the schematic drawings herewith, there is illustrated a machine for providing a downwardly directed (in use) concave reflective surface to highly polished strip aluminium alloy for use as a transverse or overhead louvre member for a fluorescent lamp (for example) . Such metal strip may be, for example, up to two metres in extension to match a fluorescent lamp disposed in use therebelow, and the machine illustrated herewith is intended to provide an appropriately shaped concave configuration of full width to the surface of that reflective louvre for subsequent disposition above the light source. The apparatus in accordance with the invention in principle comprises a frame assembly 1 having a roller conveyor 2 disposed along the upper side thereof bringing to the assembly strip metal 3 ready for appropriate concave shaping. On reaching the assembly on the roller conveyor, each individual strip, which may, as hereinbefore mentioned, be up two metres in its longitudinal configuration, is engaged by a continuous flexible belt 4 of equivalent width (formed of reinforced PVC for example) and moves towards a shaping portion 5 of the assembly. The strip 3 passes beneath a sequence of shot bolt solenoids 6 (or alternatively switch operated stopping assemblies) spaced across the machine and located above a fixed plate 7 which locate the leading and trailing edge of the strip 3 and therefore provide signals to the operating mechanism of the shaping portion 5 After passing through the shot bolt solenoids 6, each individual strip, supported by the flexible belt 4 passes through a roller assembly comprising two lower rollers 8, 9 freely rotating about parallel horizontal axes and supported by a roller support 10 from a portion of the frame assembly 1 . In addition the strip passes beneath an overhead roller arrangement 1 1 supported on an overhead roller support 1 2 and an appropriate vertically disposed slide beam 1 3 movable with respect to a fixed portion 14 of the beam frame by means of linear beam bearings. Movement of the roller support 12, 1 3 and the overhead roller 1 1 is provided, from a motor 1 6 dictated by the shot bolt solenoids 6, with a driving motion such that a cam 1 7, supported on a cam support 1 8, rotates and, via a cam follower 1 9, moves the overhead roller somewhat into the gap between the two underlying rollers to provide the necessary force on the strip as it passes therebeneath, supported by the belt, to shape, in accordance with the configuration of the cam, the necessary concave configuration to the upper surface of the strip for the required eventual reflective louvre configuration of the product concerned. Adjustment of the cam follower 1 9 and the overhead roller 1 1 is provided by set screws 20 and 21 respectively. It is to be appreciated that the continuous belt 6 is driven by roller 22, passes over a lower roller 24 and an idler roller 25, and is tensioned by means, in the arrangement illustrated, of a spring urged slide 23 and the lower roller 24 to ensure appropriate tension of the flexible belt in its support of the strip as it passes through the shaping apparatus, thereby ensuring full concave shaping across the whole of the strip as it passes through the shaping portion 1 1 . The shot bolt solenoid control arrangement associated with the shaping mechanism is of importance in that it can be arranged to control the movement and speed of movement of the belt 6 and therefore the strip 3 passing through the shaping portion 1 1 , and can also be arranged to control the cam follower 1 9 in association with the cam 1 7 to provide the appropriate shaping for the strip as it passes therethrough, and indeed can ensure an appropriate speed of operation of the apparatus such that the apparatus can operate at a rate, so we have discovered, of shaping of the strip of, say, two metres width, during a passage lasting only two seconds through the machine. Such speed of operation manifestly enables a most competitive rate of shaping enabling rapid production of shaped strip for use in concave louvre products. It is to be appreciated that along a strip of some two metres elongation, there may be provided up to a total, for example, twelve shaping roller sets to ensure accurate rolling of the total strip. It is to be understood that the foregoing is merely exemplary of apparatus for shaping metal strip and methods for accomplishing same in accordance with the invention and that modifications can readily be made thereto without departing from the true scope of the invention.

Claims: CLAIMS 1 . Apparatus for concave shaping metal strip adapted to pass the strip through a set of rolls at which appropriate concave shaping is applied to the strip by means of a shaping set of rolls, comprising a flexible supporting member adapted to support the strip in its passage through the roll set, whereby to ensure that the strip is subject to the shaping process along the total passage thereof through the shaping set of rolls. 2. Apparatus according to claim 1 wherein the supporting member comprises a belt or a web-like member. 3. Apparatus according to claim 2 wherein the belt or web-like member is of a continuous nature. 4. Apparatus according to any preceding claim wherein the roll set comprises three rolls, two of the rolls being provided for horizontally aligned parallel rotation, and the third opposed and parallel to the other rolls, applied into the gap between the first and second rolls such that during passage the strip and supporting member are subject to a deflection by the rolls and a concave forming motion. 4. Apparatus according to claim 3 wherein the third roller is capable of movement into and out of the gap between the first and second rolls during the passage of a single strip to allow a complex concave configuration to be applied to the metal strip. 5. A method for concave shaping metal strip including passing the strip through a set of rolls at which the concave shape is applied to the strip, wherein the strip is supported in its passage through the roller set by means of a flexible supporting member, whereby to ensure that the strip is subject to the shaping process along the total passage thereof through the shaping set of rolls. 6. Apparatus for shaping strip substantially as herein described with reference to and/or as illustrated in the accompanying drawings. 7. A method of shaping strip substantially as herein described with reference to and/or as illustrated in the accompanying drawings.

Inventors: NORKETT JOHN CHRISTOPHER, NORKETT, JOHN, CHRISTOPHER
Applicants: ACORN ENGINEERING GUILDFORD LI, NORKETT JOHN CHRISTOPHER, ACORN ENGINEERING (GUILDFORD) LIMITED, NORKETT, JOHN, CHRISTOPHER
Application year: 1997
Main classification: B21D5
IPC codes: B21D5