Patent GB-780753-A (GB)
Title: Machine for evacuating and sealing containers
IPC: B65B31/02
Filed: 1954-11-02
Abstract: 780,753. Seaming. STANDARD PACKAGING CORPORATION. Nov. 2, 1954 [Nov. 16, 1953; Nov. 30, 1953], No. 31678/54. Class 42 (1). [Also in Group XVII] A machine for evacuating and heat sealing bags 5 or other containers has a heat sealing bar 20 and an anvil 7 between which the mouth of the container is pressed and a hollow head 24 for evacuating the containers having an open side facing a supporting surface 6 for the containers 5 which slopes away from the anvil 7. A bag 5 is laid on the support 6 so that its mouth overlies the heat sealing anvil 7 and a pressure pad anvil 8, on a platform 4 set at an angle to the support 6. A reciprocating tube 11 moves in a bearing 10 and carries a bracket 12 having an assembly 13 mounted on a cross-head 19 which also supports the hollow sealing bar 20 fed with heated oil through conduits 31. Arms 14 carrying pressure fingers 15 are urged downwards by springs 16 and move in guideways extending at an angle to the vertical such that the arms move apart as the tube 11 and the bracket 12 descend thus smoothing out the bag mouth before it is sealed. The tube 11 carries conduits 31 through which passes the heated liquid, which conduits pass through a seal 32 above which ports 33 open into a manifold 34 connected to the main vacuum conduit 35 through a valve 37. Suction is applied through holes 9 in the sealing anvil 7 connected through a conduit 44 and a valve 47 to a holding vacuum conduit 45, which suction holds the bag mouth on the anvil prior to sealing. A valve 41 provides a vent to the atmosphere for the manifold 34 and for the holes 9 by means of a channel 70 in the shaft 43 of the valve which, as the valve 41 opens, connects the conduit 44 with the atmosphere. The valves 37, 47, 41, Fig. 10, have shafts 39, 49, 43 respectively connected to rocking arms, e.g. 52, Fig. 9, operated by corresponding cams. The main cam 60 has a groove 61 in which rides a follower 62 pivoted to a lever 63 which has a projection 64 with a roller 65 and a spring 68 the other end of which is secured to the lower part of the tube 11. The head 24 is opened by the movement of the main cam 60 which moves the roller 65 against a part 66 of the tube 11 at the upper end of which a roller 29 abuts a projection on the inside of the head which pivots at 25. A bag 5 is placed by hand on the platform 6, its mouth spread over the anvil 7. Suction is applied through the holes 9 to hold the bag in place. The vent valve 41 closes and the head 24 is lowered. The pressure fingers 15 hold the bag in place and remain in this position exerting a light pressure while the valve 47 is closed cutting off the holding vacuum and the main vacuum valve 37 is opened. After a period, when the bag has been exhausted, the valve 37 is closed and the tube 11 is further lowered. The pressure fingers 15 move apart, smoothing the bag, and the heat sealing bar 20 then presses upon the bag mouth to effect the sealing. The vent valve 41 is opened and the pressure inside the head becomes atmospheric. The head is raised and the bag falls into a shoot which deposits it on a conveyer belt. The machine is preferably of the duplex type, as is seen in Fig. 10, and has two heads. Starting and stopping is done by hand through a lever on a shaft 72. A safety device is incorporated to prevent injury to an operator by descent of the heat sealing bar. The vacuum holes 9 may impress an inscription on the bag.