APPARATUS FOR SCORING FLAT SHEETS, ESPECIALLY GLASS SHEETS

Abstract: Apparatus for scoring flat sheets, especially glass sheets, which can be used in the cutting of laminated glass with intermediate plastic layer, and in which account is also taken of the subsequent curvature of the glass. The apparatus in question consists of two units, namely: a cutting machine and a cutting template. The cutting machine is provided with a device which permits the cutting tool to score along a profile which can vary according to production requirements, with easy and rapid control of the cutting tool through a pneumatic valve (6-12). The cutting template consists of a main cutting ring (1), as well as suitably located sectors (2, 21) projecting inside side ring.

Description: PSPARATUS FOR SCORING FLAT SHEETS, ESPECIALLY GLASS SHEETS The present invention relates to an apparatus for scoring flat sheets, especially glass sheets, in order to permit their easy and precise break along the score line. The apparatus in question proves to be especially useful and it represents a step forward in the industrial field for which it is designed in that it permits a single line score to be cut on the surface of glass sheets, following any required profile along a template suitable prepared for the purpose. This apparatus is particularly suitable in the cutting of glass panes between which is laminated an intermediate plastic layer, because, as is well known, the glass panes to be used for forming the glass-plastic-glass sandwich require to be cut to the desired final size before being curved at the same time on an identical mould through a special furnace. Of the two panes of glass cut to shape, one will be used for the inside part of the sandwich and one for the outer part of the sandwich; as the glass panes are not trimmed after being curved to shape, it is necessary that the dimensions of these two glass panes, when cut from flat sheet, be such as to take into account their subsequent curvature. Consequently, the glass pane forming the outside of the sandwich, that is, the one with the greater radius of curvature, will be greater in length than the glass pane forming the inside of the sandwich which has a smaller radius of curvature. The differences in length are in the order of a few milli- metres since the differences in radius of curvature between the inner glass pane and the outer glass pane are also in the same order of magnitude. In practice, for the industrial production of such items, one short pane and one long pane of glass are required to be cut alternately for the same model. The scope of the apparatus in accordance with the present invention is to provide just the one means which, is specially equipped in order to pass rapidly from cutting of one long dimension to the cutting of a shorter dimension, without it being necessary to change the cutting template each time, or else to. double the cutting stations. The apparatus in question consists of two units: 1) a cutting machine 2) a cutting template. The cutting machine is provided with a device which permits the cutting tool to score the surface following a profile which varies according to production requirements. Said device is designed to score the flat glass sheet as required according to the one or the other of the desired profiles through simple rapid actuation of a pneumatic valve, which can be operated either manually or automatically. The cutting template consists of a main cutting ring designed to guide the cutting machine along the long profile, as well as sectors projecting inside said ring, which are suitably located and are rigidly connected to the ring, and are designed to guide the machine along the short profile if so required. The accompanying drawings, which are to be considered as an exemplification of the principles of the invention and are not intended to limit it, illustrate a preferred embodiment of the apparatus in accordance with the invention. In the drawings: figure 1 is a plan view of just the cutting template forming part of the apparatus in accordance with the invention, while figure 2 is a cross sectional view of the same template along the line A-A of figure 1; figure 3 is a partial cross sectional view of the actual cutting machine, provided with the characteristic device which permits its adaption to the long profile or to the short profile of the template illustrated in the preceding figures 1 and 2; figure 4 is analogous to figure 3 but illustrates the piston rod lowered under the spring action, instead of being raised as shown in figure 3 under the action of compressed air, and figure 5 is a front view of the actual cutting machine. Referring to the drawings (figure 1), the main cutting template, through which the cutting machine is guided when scoring the long profile, is indicated by the reference character 1, while 2, 2' indicate the additional sectors used when scoring a piece of the same shape but shorter in length, subsequently used, for example, to form the inside part of a finished laminated product. The additional sectors 2, 2' are rigidly connected to main cutting ring (template) 1 with any suitable means. Figure 3 and 4 illustrate the actual cutting machine, arranged to follow up cutting template 1, where the copying operation concerns the internal profile of said template 1 or else, when requested, the internal profile of the same template 1 but modified by sectors 2, 2' which are suitably located in this case. The cutting machine essentially consists of an air motor 3 (held in the vertical position by means of a supporting arm which is not shown in order to simplify the drawing) which commands, through reduction gear 5, the rotation of travelling wheels 4 (there are really two such wheels, but in figures 3 and 4 the second wheels is hidden by the first one) gradually along the entire outer profile of template 1 and, along that of sectors 2, 2' (when provided). This wheel movement also causes the main part of the cutting machine with relative scoring device to move along the path determined by template 1. That part of the cutting machine which permits varying cutting dimensions according to requirements, is represented in the cross sectional views in figures 3 and 5, and essentially comprises a piston 6 actuated by compressed air which causes rod 7 to slide up or down sleeve 8. The lower section of this sleeve 8 is of truncated conical shape, which, when viewed, has its minor base facing downwards, while piston rod 7 likewise ends in a truncated cone but this time, when viewed, the minor base faces upwards. Bearing 9 is keyed on sleeve 8. This bearing is blocked between suitable shoulders so that just the roraty movement of the movable bearing disc (inside the bearing) about the axis of rod 7 is permitted. A second bearing 10, with the same diameter as the other bearing 9, is fitted below the latter, and can likewise be blocked, in turn, between the two truncated conical surfaces 8', 7' of sleeve 8 and rod 7 respectively each time (as in figure 3) the compressed air, after being commanded to enter cylinder 11, thrusts piston 6 and therefore piston rod 7 upwards thereby compressing spring 12 located in cylinder 11. The internal bearing disc of bearing 10 results fixed in this case and remains locked for all the time necessary. When, as a result of a subsequent command, the compressed air passageway is opened and air is discharged from cylinder 11, spring 12 (see figure 4) is extended; piston 6 with piston rod 7 will be thrusted downwards thereby releasing the internal bearing disc of bearing 10. The end section of piston rod 7 will engage, in this case, a special recess 17 located on the apparatus, thereby leaving bearing 10 fully released. The entire unit, as described above, comprising members 6 to 12, has. provision for traversing horizontally along two guide ways 13 (only one of these guide ways is visible in figures 3 and 4, and two in figure 5 as the second guide way is on the opposite part) which also serve to support the unit. Traversing, of the unit with members 6 to 12 along guide ways 13 is opposed by springs 14 (the second spring is also on the opposite part of the assembly and is only visible in figure 5). Each one of these springs is attached first to a fixed pin 15 and then to another movable pin 16 which slides in relative slots located at end part of guide ways 13; in this way, the springs keep the cutting unit in contact with the cutting template. The actual operation of the machine will already be clear from the foregoing disclosure. In practice, when it is required to score along a long profile, that is, along the inside part of just the template 1, bearing 10 must be located in the lower position with respect to sectors 2, 2' and its internal bearing disc must have some play on on'piston rod 7; this can be achieved, as already seen, by discharging the compressed air from cylinder 11. In this case, owing to the action of spring 14, the unit with items 6 to 12, will be made to traverse towards pins 15 until bearing 9 comes into contact with ring 1. The cutting machine will then move, being powered by the air motor, along template 1 and the scoring unit will copy the internal profile of template 1 (indicated by a dashed and dotted line in figures 3, 4 and 5). At the end of this operation, compressed air again enters the cylinder, piston 6 and therefore piston rod 7 are thrusted upwards; bearing 10 will then be raised to the level of sectors 2, 2' and will remain locked between the two surfaces 7' and 8'. As sectors 2, 2' project inwards by a few millimetres with respect to template 1, the path followed by the machine will be determined at this point by bearing 10, since, when this bearing comes into contact with said sectors 2 or 2', it will cause the entire cutting unit 6-12 to move towards the left, and therefore the other bearing 9 will be retracted from cutting ring 1. To sum up: copying of the profile in the part where sectors 2, 2' are absent will be through bearing 9, and will be through bearing 10 in the part where these sectors are present.

Claims: CLAIMS OF PATENT 1. Apparatus for scoring flat sheets, especially glass sheets, comprising a cutting machine and a cutting template on which the machine is placed vertically, characterized in that the cutting machine is powered by an air motor (3) which, through a reduction gear (5), commands the rotation of the travelling wheels (4) along the outer profile of the cutting template, wherein said machine is also provided with a scoring device which permits the cutting tool to score the glass according to a variable profile in relation to production requirements, and also characterized in that said cutting template consists, in turn, of a main cutting ring (1) capable of guiding the machine's scoring device along a long profile, and of sectors (2, 2') projecting inside said ring (1), with said sectors (2, 2') being suitably located and rigidly connected to said ring (1), and also capable of guiding said scoring device of the cutting machine along a second shorter profile, if required. 2. Apparatus for scoring flat sheets, especially glass sheets, as claimed in claim 1, characterized in that the scoring device of the cutting machine comprises a compressed air actuated piston (6), moving in both -directions, whose rod (7) slides up and down a sleeve (8), and whose head acts against a spring (12) located together with the head (6) in a cylindrical chamber (11) into which enters the compressed air. 3. Apparatus for scoring flat sheets, especially glass sheets, as claimed in claims 1 and 2, characterized in that the sleeve (8), in the cutting machine scoring device, is smaller in diameter at the top and greater in diameter at the lower end which then contracts to give truncated conical surface (8'), and the piston rod (7), in turn, also terminates with a truncated conical surface (7') but widening towards the bottom this time, whereby a bearing (9), keyed to the part of the sleeve (8) of smaller diameter can be blocked between suitable shoulders, and another bearing (10) of the same diameter as the previous bearing can be blocked between the truncated conical surfaces (8', 7') of the sleeve (8) and piston rod (7), with said bearings (9, 10) being able to contact the main cutting ring (1), namely, the upper bearing (9) when the piston rod (7) is lowered and compressed air discharged with the sectors (2, 2') projecting from said ring (1), the lower bearing (10) when the piston rod (7) is raised and compressed air enters the cylindrical chamber (11). 4. Apparatus for scoring flat sheets, especially glass sheets, as claimed in the preceding claims, characterized in that said scoring device can be traversed along two horizontal guide ways (13) which also support it, and is opposed by two springs (14), at one end attached to a fixed. pin (15) and on the other to another pin (16) which slides in the slots formed in the two guide ways (13), hence during automatic operation of the machine, either one or the other bearings (9, 10) is always in contact with the cutting template, according to whether compressed air is being supplied to or discharged from the cylindrical chamber (11) in which the piston head (6) slides vertically. 5. Apparatus for scoring flat sheets, especially glass sheets, as herein described and illustrated in the accompanying drawings. diiIEhrDD CLAIMS CLAIMS OF PATENT 1. Apparatus for scoring flat sheets, especially glass sheets, comprising a cutting machine and a cutting template, the last consisting of a main cutting ring (1) and of sectors (2, 2') projecting inside said ring (1), with said sectors being suitably located and rigidly connected to said ring (1), as to offer two different scoring profiles, characterized in that the cutting machine is powered by an air motor (3) able to control, through a reduction gear (5), the rotation of travelling wheels (4) along the outer profile (1) of the template, wherein said machine is provided with a scoring device having in turn means which allow the cutting tool to score the glass according to a variable profile, long or short, in relation to production requirements, and therefore to score also two patterns of different dimensions (the one shorter and the other longer) by using the same template, which is particularly suitable in the cutting of glass panes between which is laminated an intermediate plastic layer, as used in the production of windshields for motor vehicles. 2. Apparatus for scoring flat sheets, especially glass sheets, as claimed in the claim 1, wherein the scoring device of the machine comprises a compressed air actuated double-acting piston (6), whose rod (7) slides up and down a sleeve (8) and whose head acts against a spring (12) located, together with the head, in a cylindrical chamber (11) into which enters said compressed air, characterized in that the sleeve (8) in said scoring device is smaller in diameter at the top and greater in diameter at the lower end and which then tapers off to a truncated conical surface (8'), and the piston rod (7) also terminates with a truncated conical surface (7') but widening towards the bottom, whereby a bearing (9), keyed to the part of the sleeve (8) of smaller diameter, can be locked between suitable shoulders, and another bearing (10) of the same diameter as the previous one can be locked between the truncated conical parts of the sleeve (8) and piston rod (7), with said bearings (9, 10) being able to oppose the main cutting ring (1), namely the upper bearing (9), when the piston rod (7) is lowered and compressed air is discharged, and to oppose respectively the sectors (2, 2') projecting from said ring (1), the lower bearing (leo) when the piston rod (7) is raised, and compressed air enters the cylindrical chamber (11). 3. Apparatus for scoring sheets, especially glass sheets, as claimed in the preceding claims, characterized moreover in that said scoring device is able to slide along two horizontal guides (13), which also support it, and is counteracted by two springs (14), hooked at one end to a fixed pin (15) and at the other end to a pin (16) which is movable in slots formed in the two guides (13); hence during automatic operation of the machi ne, either on or the other bearing (9, 10) is always in contact with the cutting template, according to whether compressed air is being supplied to or discharged from the cylindrical chamber (11) in which the piston head slides vertically.

Inventors: ROSSI, PIER LUIGI
Applicants: SOCIETA ITALIANA VETRO - SIV - S.P.A
Application year: 1980
Main classification: C03B33
IPC codes: C03B33