Patent GB-559964-A (GB)
Title: A method of and machines for treating black plate blanks
IPC: B23K3/08
Filed: 1942-09-04
Abstract: 559,964. Cleaning metal. TRIGGS, W. W. (American Can Co.). Sept. 4, 1942, No. 12528. [Class 82 (ii)] In the treatment of black plate blanks prior to uniting their margins by soldering or welding to form seamed cans, deoxidizing liquid, such as dilute hydrochloric or sulphuric acid, is directed along the margins longitudinally of the seam edges of the blanks whilst the latter are supported in a position for draining the liquid therefrom. Washing liquid is subsequently flowed on each margin but over a wider area than that covered by the deoxidizing liquid, the lower edges of the blanks are then blotted by contact with absorbent or blotter rollers, the margins subjected to air blasts and then to the action of radiant heat. The blanks S are fed one at a time from a stack 31 contained between supports 32 mounted on a table 33 carried by a main frame 34 by a flexible cup suction separator 42 connected to a source of vacuum and mounted on a slide which is vertically reciprocable within a bracket 41 by linkage with an eccentric 44 on a shaft 45 connected by a clutch 46 to a main shaft 47 driven by an electric motor 50, the clutch 46 being operated by an electromagnet 51. When the blank is placed on the table 33 by the separator 42 a valve in the vacuum line is opened by the operation of a bell crank 66 connected by a link rod 67 and a lever 68 to a shaft 58 which is operated through a link 61 connected to the eccentric 44. The released blank is then engaged by a pair of dogs on a slide 76 which is reciprocated in guideways in the table 33 by a link 79 connected to a crank 78 on a shaft 81 mounted in a bearing 82 formed in an adjustable slide 83 set in ways 84 cut in the upper part of a housing 85 mounted in the base 35 of the frame 34 and driven by bevels 86, 87, the adjustment of the slide for different sizes of blanks being effected by the operation of a threaded shaft 91 journaled in a bearing 92 in the casing 85 and in a lug 96 formed in the under surface of the slide and as each blank is advanced over the table 33 it is attracted towards the latter by a series of permanent magnets 101 mounted in but below the table so that frictional engagement between the blank and the table is increased. Other dogs 102, yeilding and mounted on the slide 76 in advance of the dogs 75, move the blank forward and the latter is moved by other dogs until it reaches the end of the table 32. Guide plates are slidably mounted in the table on transverse screwed shafts connected together by endless chain and operated from outside the table so that they can be adjusted to take blanks of different widths. At the end of the advance of the blank by the slide 76, the forward end of the blank is stopped and engaged by a cushioning device 121 and as the slide recedes, the blank is picked by a pair of prongs 122 secured to conveyer chain 123 running over sprockets driven from the shaft 47 by bevels 126, a shaft 128 and bevels 136 mounted on a shaft in bearings 138, 139, 140. As the chains pass over the reservoir frame they are guided by rails 170 and the blanks are turned into the vertical position during which they are confined in a chamber 171 housed in frame 172 and provided at the top with a ventilating outlet. Showers of deoxidizing fluid are then directed downwardly on the upper edge of the blanks so that it flows only over the side margins by nozzles 185, Fig. 11, which are mounted in manifolds 183 provided with chambers 186 connected by flexible conduits 182 with a header 181 connected by a conduit 179 to a pump 178 in turn connected to a conduit 177 bv which acid is withdrawn from an acid bath 176. The acid enters the nozzles 185 from the chambers 186 through a restricted entrance into an expanded orifice which extends to the discharge ends of the nozzles. The blanks are then carried over a water bath 195 and under nozzles 196 which are fed by a pump from the bath 195, a plurality of nozzles being provided opening from a water header so that wider portions of the blanks are washed with water than were treated with acid. The blanks are then conveyed past rollers 205 covered with absorbent or blotting material which removes some of the water therefrom and then pass over cam rails 271 which turn them gradually from the vertical to the horizontal position when they are deposited on a table 206 supported on a frame 207 carried by the main frame 34. Both the acid bath 176 and the water bath 195 may be heated by perforated steam pipes 214 which are connected to a source of supply in pipe 211 through a thermostat-controlled valve 212 and a pipe 213. The nozzles 185 and 196 are mounted so that they can be adjusted horizontally and vertically. When the blanks are freed from the conveyers 123 they are deposited, one by one, on conveyer belts 272 which carry them under and in contact with upper and shorter belts 273, both being driven from an independent motor adjustably mounted in an end wall of the frame 34. Any moisture still remaitiing on the marginal edges of the blanks is removed by air from air blast units 326 mounted on the frame outside the conveyers, these units being provided with upper and lower nozzles which project air on to both sides of the edges of the sheets, the moist air produced passing away to a baffle chamber where the moisture is collected. The blanks are then moved under radiant heaters 365 and to prevent the burning of the upper and lower belts 272, 273 water is circulated through the chambers 371, 372. The dried blanks are discharged by the belts into a stack retaining device 372 from which they are released by the actuation of a lever and fall, guided by members 397 in to a truck 422, which is mounted on rails so that it can be pushed out of the position.