APPARATUS FOR FORMING A PERIPHERAL FLANGE ON A FLAT DISC

Abstract: Apparatus for forming a peripheral flange on a fiat disc of sheet material, particularly to make an end cover for a coil of steel strip, has support (1) for the disc which is stepwise rotatable about an axis (2) by a stepping mechanism, clamping means for clamping the disc to the support, and a shear (32) for cutting a radial slit in the circumference of the disc after each step. Bending means (34) bend, out of the plane of the disc, the area of the disc material between each adjacent pair of slits so that said areas together form the flange To avoid eccentricity of the disc, means for centering the disc on the support before clamping are provided, and comprise at least three centering elements (27, 28, 29) which are spaced apart from each other around the circumference of the disc and are connected to driving means (16, 30)) so as to be all at the same distance from the axis of rotation of the support (1) and to be all radially movable simultaneously and at the same speed so as to engage the circumference of the disc.

Description: "Apparatus for forming a peripheral flange on a flat disc" The invention relates to apparatus for forming a peripheral flange on a flat disc of sheet material, comprising a support for the disc which is stepwise rotatable about an axis by a stepping mechanism, clamping means for clamping the disc to the support, a shear for cutting a radial slit in the circumference of the disc after each step in the rotation of the support so as to form a plurality of radial slits, bending means for bending, out of the plane of the disc, the area of the disc material between each adjacent pair of said slits so that said areas together form the flange. Apparatus of this kind is known from British Patent Specification 1532396. The particular purpose of the apparatus is to provide a flanged disc of sheet material, for instance thin sheet steel, for use as the end cover in the protective packing of a coil of steel strip. This type of packing is described fully in GB 1532396.The apparatus may be adjusted in correspondence with the diameter of the coil to be packed. This is effected by moving the notching shear and bending device radially on slides. If the circular disc is provided with a concentric coiler hole, the centering of the disc on the support platform does not present any problems. The situation alters, however, if, as is sometimes required for packing purposes, a flange needs to be produced without a coiler hole. The invention aims to provide apparatus of the type described here in which centering may easily be accomplished. The invention is set out in the claims. In this way it is possible for all types of disc, with or without a centre hole, to be simply and rapidly centred on the support platform. An embodiment of the apparatus is illustrated in the accompanying drawing and will now be described with reference thereto, by way of example. Fig. 1 is a schematic top view of the apparatus embodying the invention for making a flange for packing a coil of steel strip from a disc. Fig. 2 is a side view and Fig. 3 a front view of the notching shear with two sensors employed in the apparatus of Fig. 1. Fig. 4 shows the attachment of the centering roller to the chain in the apparatus of Fig. 1. Fig. 5 shows the tensioner incorporated into the chain, in the apparatus of Fig. 1. The apparatus as shown in Fig. 1 has a horizontal, round support platform 1 which can be progressively rotated around a vertical axis 2 in a clockwise direction by means of a stepping mechanism 3 which is shown by a dotted line under the platform 1 and which has the pinion 4 in mesh with the cog wheel 5 coupled to the axle 2. A complete revolution of the platform 1 may for example consist of 36 steps each of 10 degrees. The platform 1 and the drive mechanism are attached to a frame which stands on legs on the factory floor. The frame comprises among other things, a number of beams 6,7,8,9 and 10 extending horizontally from the platform 1. Each of these beams is provided in the centre of its upper surface with a narrow horizontal ridge numbered 11,12,13,14 and 15 respectively, to provide a bearing surface for the disc to be worked on. The minimum diameter permitted for this disc is indicated by chain-dot circle A, and the maximum diameter indicated by the chain- dot circle B. A disc positioned on the support platform 1 and the support ridges 11 to 15 may be fastened with respect to the revolving platform 1 by means of a clamping disc not drawn in Fig. 1 but to be imagined above the plane of the drawing - which is attached by means of a pneumatic cylinder to a gantry construction resting on the legs 8a and 10a extending from beams 8 and 10 in such a way that, when the aforementioned cylinder is activated, the disc to be worked on is held tightly in place and performs all the stepping movements together with the platform 1. The clamping disc is able to rotate with the platform 1. This method of clamping enables discs of varying diameters with or without a centre hole to be held tightly in place. Before the disc positioned on the table 1 and the bearing ridges 11 to 15 is clamped#into place, however, it is necessary for the disc to be centered relative to the axis 2. For this purpose, a three-point centering mechanism is fitted, in which the three points are always located at the three vertices of an equilateral triangle the sides of which may vary but the centre of gravity of which is always located at the centre line of the axis 2. This mechanism consists of an endless chain 16 which is arranged beneath the upper surface of the beams around sprocket wheels 17,18,19,20,21,22 and 23 attached to these beams and approximately has the shape of a three pointed star. The corresponding sides 24,25 and 26 of this star between the sprocket wheels 17 and 18, 19 and 20, 22 and 23 respectively extend radially towards the centre of the axis 2 and furthermore are spaced from each other at 1200 around the axis 2. These three sides 24,25 and 26 of the chain 16 are respectively connected, at equal distances from the axis 2, to three upright pins numbered 27,28 and 29 respectively. These pins are designed as vertical rotatable rollers and are mounted in bearings of synthetic plastics material. Fig. 4 shows how a roller of this nature (27,28 or 29) is attached to the chain 16, namely by means of an inverted, U-shaped clamping frame 40 which is clamped onto the chain by an adjustable block 41 and bolts to go with it. The chain 16 is driven by a pneumatically operated cylinder 30 which effects rotation of its vertical projecting axle 30a. The axle 30a carries the driving gear 22. A chain tensioner 31 is incorporated into the section of the chain located between the widest spaced sprocket wheels 18 and 19 so that the tensioner 31 never needs to run over a wheel as the chain 16 moves backwards and forwards. Details of this tensioner 31, which is otherwise conventional in nature, are shown in Fig. 5, and do not require any further explanation. When the cylinder 30 is activated, the chain 16 is first moved to the right so that the pins 27,28 and 29 move towards the centre at the same time and at the same speed and thereby take the positioned disc with them, and thereby centre it on the axis 2. As soon as this has happened, the power of the cylinder 30 is reversed by the operator using a push-button control, so that pins 27,28 and 29 move back outwards to occupy the original position shown in Fig. 1. The adjustable block incorporated into the section of chain 26 (Fig. 1) is provided with a laterally projecting lug (not shown) to operate a limit switch to switch off the power to the rotating cylinder 30 as the chain moves backwards as described. Once centering has been completed, the aforementioned clamping devices is activated and the stepping movement commences. A pneumatically operated notching shear 32 is mounted on a radially movable slide 33 so that the shear 32 can be adjusted to notch the circumference of discs of varying diameters. The shear 32 can make a radial incision of for example 10 centimetres in length in the centered and clamped disc; the successive incisions which are made as the disc is progressively rotated result in a number, for example 36, of radially outwardly extending strips on the circumference of the disc. The shear 32 is succeeded, in the direction of rotation, by a bending device 34 at an odd multiple of half the stepping distance, this bending device being mounted radially movably on a slide 35 to allow adjusting of the bending device 34 to the various disc diameters. The two slides 33 and 35 are movable simultaneously and and at the same speed. To show whether a disc of the correct diameter has been presented to the device, two sensors 36 and 37 (designed as approximation switches) are mounted radially on the slide 33 of the notching shear 32 to ascertain the presence of a positioned and centered disc under the notching shear, and also whether it has been correctly centered and has the correct diameter (too large/too small). This is shown in more detail in Figs. 2 and 3.

Claims: mss 1. Apparatus for forming a peripheral flange on a flat disc, of sheet material, comprising a support (1) for the disc which is stepwise rotatable about an axis (2) by a stepping mechanism, clamping means for clamping the disc to the support, a shear (32) for cutting a radial slit in the circumference of the disc after each step in the rotation of the support so as to form a plurality of radial slits, bending means (34) for bending, out of the plane of the disc, the area of the disc material between each adjacent pair of said slits so that said areas together form the flange, characterized by: means for centering a disc on the support before clamping so that the centre of the disc coincides with the said axis of rotation of the support (1), which centering means comprises at least three centering elements (2?,28,29) which are spaced apart from each other around the circumference of the disc and are connected to driving means (16,30) so as to be all at the same distance from the axis of rotation of the support (i) and to be all radially movable simultaneously and at the same speed so as to engage the circumference of the disc, thereby to move the disc so as to centre it. 2. Apparatus according to claim I wherein there are three of said centering elements (27,28,29) arranged so as to be always at the apexes of an equilateral triangle centered on the axis of rotation of the support (1). 3. Apparatus according to claim 1 or claim 2 wherein said driving means includes an endless chain (16) which moves along a fixed path including a plurality of portions (24,25,26) extending radially with respect to the axis of rotation of the support (1), the centering elements (2?,28,29) being respectively connected to said radially extending path portions (24,25,26). 4. Apparatus according to any one of claims I to 3 wherein said centering elements (27,28,29) are upstanding pins. 5. Apparatus according to claim 4 wherein the pins (27,28,29) are rollers made of metal and mounted in plastics material bearings. 6. Apparatus according to any one of the preceding claims wherein two sensors (36,37) are mounted adjacent the shear (32), to provide an indication whether the disc is correctly centered and/or is of correct diameter.

Inventors: VOS, BARTHOLD ULFERT
Applicants: HOOGOVENS GROEP B.V.
Application year: 1981
Main classification: B21D43
IPC codes: B21D43, B65B25, B23Q3, B21D51, B21D53