Patent GB-525522-A (GB)
Title: Improvements in method of and apparatus for canning
IPC: A23L3/04
Filed: 1939-03-30
Abstract: 525,522. Preserving food. AMERICAN CAN CO. March 30, 1939, No. 10001. Convention date, April 2, 1938. [Class 49] [Also in Group XXX] In canning food of the discrete particle type, the filled cans a are introduced with tops open into a sterilizing chamber G maintained by steam at high temperature and pressure, the cans are inverted whilst holding the contents therein, live steam at a temperature and pressure above that in the chamber is introduced directly into the inverted can to sterilize the product and remove gases therefrom, the condensate draining from the can, and hermetically sealing the can whilst still in the sterilizing chamber. As shown, the filled open-topped cans a pass along a runway A into a rotary pocketed valve B which introduces them into a preheating chamber C, preferably maintained by steam at 220‹F., through which they are taken by a rotary pocketed turret D. The cans are next transferred by a rotary valve E one at a time into a star-wheel F which transfers them on to the upper run of an endless chain conveyer H. The conveyer H consists of links 81 pivoted together by cross-shafts 82 which have supporting-rollers 83 at each end, which move on tracks 105 with side rails 108 in the upper run, and on rails 111 in the lower run. A unit J for supporting and screening the can is carried on each pair of shafts 82 and consists of a block 84, Fig. 6, through which the shafts 82 extend. A can-supporting platform 91 is mounted on a rod 86 sliding in the block 84, a spring 92 being interposed so that the platform presses the can up against a perforated plate 94 carried by posts 93 mounted on the block. The rod 86 carries a wheel 99 which engages a cam 107, Fig. 3, to lower the platform 91 to receive a can from star-wheel F. As the conveyer moves on the roller 99 leaves the cam 107 and the can is clamped in position with its open top against the plate 94 ; it is then carried down to the lower run of the conveyer where it passes inverted under jets of steam at 297.7‹F., supplied through nozzles L from a pipe M, the chamber G being kept at 280.6‹F. by steam supplied by pipes 112. Overhead steam jets are also included which project steam directly into the open tops of the cans. The can is next righted and pass again to the upper run of the conveyer, on which the platform 91 is lowered by engagement of roller 99 with a cam 121, Fig. 4, and the can is pushed off by a finger 122 of a rotating star-wheel O and is engaged by one of a series of fingers 127 carried on a rotatable body portion 128 of a transfer-device P. The fingers 127 may be pivoted and be actuated by a fixed cam plate 125 so as to ensure proper engagement with the can and slowing down and acceleration of the can travel, allowing the can to be held for sufficient time under a nozzle R for supply of brine. The can next passes to an intermittently moved turret S which takes it to a transfer device T consisting of a disc 141, Fig. 8, with can-retaining fingers 142, slidable on a support-plate 129 and actuated by a lever 145 which moves it between the turret S and a star-wheel U. The cans are taken by wheel U to a seaming head V to which each can is raised by a plate 169, and picks up a cover b supplied from a stack by a reciprocating feed slide 161. The covers b are supplied from a feed-device W having two pockets 151 filled through openings 153, with cover-plates 154, in the casing 152. The device W is rotatably mounted on a plate 156 so that the pockets may be registered in turn with an opening 157 leading to a channel 158 extending to the feed-slide 161. The slide 161 is reciprocated by a lever 165 and carries a spring-pressed finger 166 which on the first movement of the slide engages the lowermost cover b and takes it to an intermediate position 168, the slide then returning to the former position ; in the next forward movement the finger 166 feeds the cover to beneath the seaming head V. The sealed can is taken by star-wheel U to transfer-device T, which carries it to turret S from which it is carried along guides 171, 172 by an endless chain conveyer Y back to conveyer H which meanwhile has been cleaned by streams of hot water or other cleaning fluid supplied through nozzles 192 from a pipe 191. The sealed can is clamped on conveyer H from which it is, after unclamping, removed by, a star-wheel AA, Fig. 1, to valve E, which transfers it to a rotary pocketed elevator BB, Fig. 7, which by means of a helical guide 205 raises it to a discharge-valve CC which transfers it to a water bath EE. The elevator BB is disposed in a cooling chamber DD supplied with jets of cold water from a manifold 207 and maintained at a pressure of about 25 lb. per sq. in. by compressed air supplied through a pipe 208.