Patent GB-1251364-A (GB)
IPC: B24B9/10
Filed: 1968-11-15
Abstract: 1,251,364. Grinding. PERMAGLASS Inc. 15 Nov., 1968 [5 Feb., 1968], No. 54232/68. Heading B3D. [Also in Division C1] In the cutting and grinding of glass or like sheets, a sheet is positioned relative to an axis, the sheet being cut by cutting means to a predetermined pattern by controlling the position of the cutting means relative to the axis during relative movement between the sheet and the cutting means and grinding the periphery of the cut sheet by grinding means by controlling the position of the grinding means relative to the axis during relative movement between the sheet and the grinding means, the sheet being maintained in the same position relative to the axis. Two glass sheets A and B are held either side of a shuttle block 36 on the axis 26 for cutting and grinding respectively by cutter 128 and grinding wheel 117, the sheet 6 having previously been cut as sheet A. The shuttle block 36 is moved from and to the cutting and grinding position by a conveying means 30 to a second position where a new sheet A is clamped to the top and the previously cut and ground sheet B is passed to a roller conveyer 95. At the same time, the new sheet A is being collected from a suction plate 93 which has previously been moved down by piston 94 to collect the next sheet from the conveyer 95. During the operation, the newly cut sheet A is repositioned to become sheet B by downwardly moving, along axis 26, clamping member 32 to which it is held by vacuum where it is then released on to lower clamping member 34. In the operative position, the clamping member 32 clamps the sheets to block 36 and member 34 and a template 66 (Figs. 2-11) or 202 (Fig. 14) is secured by plate 67 or 67<SP>1</SP> to a sleeve 52 on shaft 51 holding the clamping member 32, the whole being rotated by motor 38 actuating member 34 or by template 202 from motor 220. Shuttle block.-The shuttle block 36 is rotatably supported (Fig. 11) in an annular housing 70 supported between shafts 71 with some degree of flexibility, the outer ends of which are connected to L-shaped carriers 73 (Figs. 9, 9a) having a groove (75) to engage over a V-belt 74 extending over pulleys 76, 77, pulley 77 being driven alternately in opposite directions from shaft 78 by an oscillating rack (79) to move the block 36. The block 36 has grooves 88, 88<SP>1</SP> in lower and upper faces communicating with annular recesses 89, 89<SP>1</SP> by passages 90, 90<SP>1</SP> and thence through passages 91, 91<SP>1</SP> in shafts 71 and flexible hoses to a source of vacuum for holding, respectively, sheet B on return from, and sheet A to, the operative position.  Gutting and grinding means.-The grinding wheel 117 and cutter 128 are mounted on a carriage 110 movable along guide bars (111) towards and away from axis 26, the grinding wheel being rotated by motor 118 about axis 119. The grinding wheel 117 is annular and surrounded by a splash shield 120 rotatably mounted on carriage 110 by bearings and with a slot 122 for the glass sheet B. Cutter 128 comprises a wheel rotatably mounted on a piston-rod (132) for pressing downwardly against the glass sheet A with a back-up roller 129 below, the cutter wheel 128 being mounted at the end of upper leg 124 of a U-shaped member 123 which is mounted by lower leg 125 on the splash shield 120 and can therefore oscillate about the axis 119, as required to maintain the cutter wheel 128 perpendicular to the glass sheet A, the shield 120 being oscillated from a motor 134 (Figs. 2-11), of by template 202 from motor 220 (Fig. 14).  Control means.-On the first embodiment, Figs. 2 to 11, a sensing means 140 on leg 124 is aligned with cutting wheel 128 and grinding wheel 117 and reads the template 66 for controlling the movement of the carriage 110 and the shield 120 and as shown, comprises a pair of photo-cells 141, 142 (Fig. 4) to measure light intensity either side of a periphery line 143 on template 66, for example white paper one side of the line and black the other. The photo-cells 141, 142 are balanced for equal illumination and if the cutter wheel 128 becomes non-perpendicular to the glass sheet A, the periphery line becomes 143<SP>1</SP> when the servo-valve is operated to start motor 134 to move shield 120 till wheel 128 is again perpendicular. The photocell 142 is calibrated to maintain the path of the template 66 so that when line 143 is displaced either side, e.g. to 143<SP>11</SP>, the servo-valve to cylinder 114 operating the carriage 110 will be energized to move to the cutter wheel 128 and grinding wheel 117 into the template periphery. A measuring wheel 144 (Fig. 2) is provided through a tachometer to the motor 38 to control the speed of rotation of the template 66 and glass sheets A and B so as to maintain substantially constant the tangential velocity between the periphery of the sheet and the cutting wheel 128 and grinding wheel 117. In a second embodiment (Fig. 14) the control means comprises a roller 206 supported on a block 212, which is rigidly mounted on the leg 124, and engaging the inside of cam track template 202 and a pair of rollers 208 engaging the outside, the track 202 being larger by the radius of roller 206 than the final periphery required in the glass sheets. The template 202 and glass sheets are rotated by pressure from driven rollers 208, springs 224 connecting the rollers 208 to roller 206, the rollers 208 being driven from motor 220. The rollers 208 are mounted to maintain the cutting wheel 128 perpendicular to the glass by shafts, rotatably supported on a member 216 slidably mounted on the leg 124 by a bracket (218), a key 219 on leg 124 extending through slot 217 to maintain member 216 perpendicular the leg 124. Therefore if the member 216 is pivoted by the cam track, the cutting wheel 128 will be similarly pivoted. The speed of rotation of the rollers 208 is maintained substantially constant by a control means in motor 220 to maintain the tangential velocity between the periphery of sheet B and the grinding wheel 117 substantially constant.