Patent GB-621113-A (GB)
Title: Improvements in plants for the treatment of asbestos-cement or like sheets in the plastic state
IPC: B65G43/08
Filed: 1945-06-08
Abstract: 621,113. Conveyers. TURNERS ASBESTOS CEMENT CO., Ltd., and ROOKSBY, W. H. June 8, 1945, No. 14591. [Class 78 (i)] A plant for use in converting asbestos cement sheets into finished products comprises a sheet-forming machine, operating apparatus and endless belt conveyers to convey the sheets to each apparatus in turn characterised in that some of the operating apparatus are intermittently driven, the conveyers which deliver to such apparatus are also intermittently driven, and the controls of all the intermittent drives are operated in turn by each sheet delivered from the making machine. An asbestos sheet, built up of successive laminations on cylinder Y, is cut and falls on to conveyer A (Fig. 1) which is started by the operator. The sheet passes down main conveyer line B, G, H, I, J, to produce coloured slates when the rod 41 (Fig. 8) controlling switches S27, S30, S31, S38, S39 is put out of action : the sheet passes down branch line B, C, D, E, F to form a finished uncoloured sheet when rod 41 is moved to the left, and passes down branch line B, C (to the right) to form an uncoloured corrugated sheet when rod 41 is moved over to the right. Suppose uncoloured corrugated sheets are required. The sheet moves along conveyer A and slides down inclined plate 21 (Fig. 2A) to close switch S.1 and so to start motor M2. The latter drives pinion 39 to cause conveyer B to move bodily forward along frame 19 until projection 45 on the conveyer engages simultaneously switches S2, S34, S35 on the frame. Thereby, conveyer B is stopped, and set bodily in reverse, whilst at the same time motor M3 is started and rotates conveyer belt B forward at the same speed as the frame moves backward so that the sheet is laid on to slat conveyer C gently. As the conveyer moves backward projection 53 on its frame engages switches S4, S36, S37. Thereby M2 and M3 are stopped, and M4 (Fig. 4A) is started so that conveyer C moves bodily to the right towards corrugated former W (Fig. 2A). Projection 63 on the frame of this conveyer engages switches S8, S40, S41. so stopping motor M4 and starting motor M5 so that its band 70 rotates and the sheet moves over the end on to former W. As it does so it closes switch S5, and conveyer C moves bodily backwards allowing the sheet to lap on to the former W (Fig. 6). In the end-trimming apparatus K the sheet ends are first cut off by knives 77, 78 driven by motors M6, M26, and the waste collects in bottomless shoes 71, 72 and then falls through. openings 81, 82 in the slats of conveyer C. To avoid an oncoming sheet dropping through the openings, motor M5 continues to run till conveyer band has completed one revolution when it is stopped by the engagement of projection 83 with switch S22 (Fig. 4A). Also projection 68 on conveyer frame engages switches S42, S43. Thereby motor M4 is stopped and motors M7, M8, M9 of the apparatus L are started up for trimming the other sides of the sheet by means of two inclined rotary knives 102, 103 mounted on reciprocating carriage 100 which moves upon rails 113. The carriage engages switches (not shown) to stop motor M9 at end of traverse, to - reverse it, and finally to stop all three motors. Waste cuttings are deflected by ploughs 117, 119 to slide into a hopper 123 (Fig. 4). The sheet is then lifted by suction box 130 of apparatus Q2 of the type disclosed in Specification 621,111 and deposited on trolley 129. The stack of sheets is interleaved by templates transferred by a similar apparatus Z2 from trolley 134. If uncoloured flat sheets are required the rod 41 is pushed to the left. This causes the motor M5 to run in the opposite direction and the sheet to be conveyed to the left so that on falling over plate 201 it engages switch S6 causing M4 to start so that the frame 60 of conveyer C moves backward and the sheet is gently deposited on conveyer D. The conveyer frame 60 moves backward till its projection 63 operates S41 to start motor M21 which drives conveyer D and M17 which drives conveyer E. The sheet passes to conveyer E and is conducted past suction box 210 and beneath rollers 211, 212, (also driven by M17) which press downwards on the sheet (Fig. 2C). In passing on to conveyer F the sheet actuates switches S16, S46, S52, whereby M23 (not shown) is started up to drive conveyer F and the sheet then engages switches S15, S47, S54 so that M23 is stopped to bring the sheet to a halt opposite the endtrimming apparatus U similar to trimming apparatus L, and M24 and M25 are set in motion to drive rotary knives 244, 245 which traverse the width of the conveyer on adjustable frames 240, 241 and are reversed with the aid of a time switch. The next oncoming sheet actuates switch S16 again and re-starts motor M23, and the first sheet goes forward till it stops opposite stacking apparatus Q1. Previous actuation of S54 sets this in motion and the apparatus runs through a cycle of operations similar to that of Q2. When coloured products are to be made the main line is used. A selector switch S10 (Fig. 8) is used so that of 4 sheets one or more may pass down the main line, the rest being passed to the left or right as required. The switch has rotary drum 250 with contact strips 251, 252, 253, 254 cooperating with pairs of contacts 255, 256, 257, 258. Also, on the underside of frame 34 of conveyer B, is counter rotor indicator 260 having an arm 261 on shaft 270 to which pinion 271 is connected through one-way clutch 272. The pinion 271 engages rack 273 on frame 34 and is turned through 90‹ every time the frame moves forward. When the selector switch S10 is in its first "on" position strip 251 closes contacts 255 and a circuit is completed every time arm 261 bridges contacts 262. As a result solenoids 270, 271 are energised to close S58 and open S59, S60, S61. This prevents the starting of M3, M5 and the frame of conveyer B moves forward to conveyer G for one sheet in four. If the selector switch is turned further so that strip 251 bridges contacts 256 and strip 252 bridges contacts 255 then two sheets in every four will pass down the main conveyer, and so on. Projection 45 on frame of conveyer B engages switches S3, S55, S56, S57 on frame 19 so that M2, M3 stop and motor M12 (not shown) starts up con-' veyer G which carries sheet beneath state-cutting press V, and time. switches TS2, TS3 are actuated so that after the interval required for the sheet to pass on to conveyer G motor M3 is stopped and M2 reversed. Finally conveyer B operates S4 and stops. Slate-cutting press V comprises head 141 with cutting edges 142 extending downwards which is reciprocated by hydraulic ram 143 driven by motor M13. The sheet stops ; head descends, pauses and rises ; and toothed chains 145 driven by motor M29, which is started by projection 146 on the head contacting switch S28 move transversely across conveyer G to carry trimmings away. Press and conveyer operate automatically by the engagement of switches S17, S62 by an oncoming sheet, and the cut sheet is delivered on to conveyer H which feeds continuously into colouring unit N of the type described in Specification 621,112. The coloured slates pass over S18 (Fig. 2E) so that as they pass on to conveyer I it is set in motion by motor M15 and conveys them to oven O, where they strike switch S20 which in conjunction with a time switch holds the slates stationary for a certain time in the oven. After this, conveyer I moves forward and the slates operate S19 which starts M16 of conveyer J. On this conveyer suction is applied by apparatus P to remove excess colouring and the slates pass through smoothing roller, PP. The slates are stopped opposite lifting apparatus Q by the actuation of switches S21, S25, by the oncoming set of slates and the slates are lifted over on a trolley by a similar apparatus to that described above. To produce large coloured sheets the cutter 142 of press V is replaced by end trimmers. To produce coloured corrugated sheets conveyer J is run continuously and lifting apparatus Q is disconnected so that the sheet from conveyer J falls on to conveyer B1 which delivers them to conveyer C1 which laps them on to former Wl and they are then stacked by lifting apparatus Q3 as before. Specifications 621,110, [Group V], 621,135 and 621,136 also are referred to.