Patent GB-147706-A (GB)
Title: Improvements in or relating to machines for sealing containers in vacuo
IPC: B65B31/02
Filed: 1920-07-08
Abstract: 147,706. Townsend, H. E. July 8, 1920. Capsules and the like, applying.-Relates to a machine for sealing in vacuo receptacles containing foodstuffs and comprises means for feeding filled containers from a moving conveyer both into the machine, means for enclosing each container in a vacuum chamber, and for actuating the chamber and the sealing device by air pressure, means for preventing the starting of the machine until the air pressure in the exhaust chamber has been reduced to a predetermined point, and in providing an exhaust chamber and a pump within the frame of the machine. The machine comprises a column 11, Fig. 2, on which revolves a cylindrical carrier 14 that supports a table 19 and the cylinder 20 for operating the vacuum chambers and sealing devices. Each sealing device consists of a cylinder 20 to the pistons of which a tube 24 is secured, and a bellshaped vacuum chamber 27 is slidably mounted on the lower end of the tube. The chamber seats on the table 19 when the piston is lowered and forms an air-tight chamber enclosing the container. Slots 36 are formed in the tube to provide communication with a space 31 formed in an extension 25 of the cylinder, and pipes connect the space 31 and the upper ends of the cylinder respectively to a stationary valve 62 which is seated in the top of the carrier 14. A sealing-plate 34 is secured to the lower end of the tube 24, and holes 38 in the tube provide communication between its interior and the interior of the chamber 27. In use, air is exhausted from the space 31 thus causing the piston to move downwards and enclosing the container in the vacuum-chamber 27. Continued downward movement of the piston first uncovers the hole 38, so that the air is exhausted from the chamber 27, and finally causes the plate 34 to push the closure down into the mouth of the container. The rotation of the carrier 14, by its movement relative to the valve 62, admits air to the space 31 and exhausts air from above the piston and raises the chamber. The column 11 is utilised as an exhaust chamber 11' by providing it with a head 41 and with a partition near its lower end, and the air pump 43 is secured to the head 41. The piston 45 is secured to a tube 47 which passes through glands in the head 41 Bind the partition 40 and is connected at its lower end to a bell crank lever 83 rocked by the driving-shaft of the machine. Holes 48 in the tube provide communication between the chamber and the space above the piston, and a tube 49 provides communication between the chamber, the space below the piston, and the valve 62. The upper ends of the tubes 47, 49 are closed by valves 52. Thus the reciprocations of the piston 45 exhausts air from the chamber 11<1> and, through the valve 62, from the cylinders 20. In order to prevent the carrier 14 from being rotated until the air has been exhausted from the chamber 11, the driving-shaft 79, Fig. 3, of the machine is connected to the bevel wheel 91 of the gear that rotates the carrier by means of a clutch 154, and this clutch is kept in engagement by an air cylinder 160 connected with the chamber 11<1>. Thus when the machine is started, rotation of the driving-shaft operates the air-pump 43, but not the carrier 14, until the pressure in the chamber 11<1> is low enough to cause the piston of the cylinder 160 to lift and engage the clutch 154 against the pull of a spring 166. The device for feeding the containers to, and removing them from the table 19, consists of a conveyer belt 106, Fig. 3, curved guides 111, 115, and horizontal arms 117 projecting from a vertical rotating shaft. In order to obtain a regular feed of the containers into the machine, they are spaced evenly along the conveyer 106 by arms 136 which are reciprocated horizontally above the surface of the conveyer. By engaging any container that may be out of position, they retard its travel for a short time and eventually move it into its correct relative position on the conveyer.