METHODS AND MEANS FOR LID STERILIZATION

Abstract: The present invention presents methods and means for lid sterilization and temporal sealing. With the lid sterilization means, a lid's whole surface is completely sterilized, while it is held and revolves, and the lid then is put on the opening of a container which is hung at its flange on a pair of rail and carried by a pushing plate. With the temporal sealing means, the lid is partially pushed on the flange by a heater and is briefly and temporarily sealed.

Description: The invention relates to a method according to the preamble of claim 1 and to means according to claim 3. So-called fill-and-pack in a non-germ atmosphere methods are frequently desirable in comparison to regular methods. A fill-and-pack in a non-germ atmosphere method may involve sterilizing food prior to filling the food into a container and then sealing the container with a lid in a non-germ atmosphere. The container and the lid are also sterilized beforehand. Regular methods on the other hand, involve filling and packing in a clean atmosphere, which contains germs, and sterilizing the food and the container together by applying heat or hot water thereafter. The former method is considered better than the latter one for the following reasons: Food is sterilized with high temperature in a very short time, therefore the quality of the food remains good for a long time. Since food is sterilized and filled in a sterilized container, it contains no germs and therefore will not rot even if it is kept long time at normal temperatures. Keeping food cold is not necessary, so that energy otherwise needed for cooling the food can be saved. Food can be filled in a bigger container than a can for canned food. Thus it is more economical. Food can be saved in a warehouse and on a shelf for a long time, thus production of the food can be well planned. The container is sterilized by means other than heat before the food is filled, therefore heat-proofing is not required. There are at least two ways to complete the method for fill-and-pack in the non-germ atmosphere: one is to seal the container with a film-like lid material and cut it to a lid shape thereafter; the other is to seal the container with a lid that has previously been cut or punched to a lid shape. The former type, however, has a number of problems. For example, it is extremely difficult to keep the non-germ atmosphere of the apparatus since it is necessary to create an open passage between the inside and the outside of the apparatus to supply the film-like lid material. Therefore, the latter type is considered more convenient. The latter type---previously cut a lid in shape---is described in Japanese patent laid open application No. 59-115221. In this embodiment, each lid is held by a rod which moves by an endless chain, and as the lid moves it is sterilized, dried and then supplied on the container for sealing. After the lid is put on the container, it moves to a next step and there the lid is pressed by hot heat and sealing is completed. The problem of this embodiment, however, is that since the container moves with a lid to the next hot press step, the lid often moves from the first set position and the lid then can be sealed on the wrong distorted position. This could produce incompletely sealed products having a poor appearance. Japanese utility model laid open publication No. 57-193602 attempts to resolve the above-mentioned problems by including means that correct the position of the lid put on the container, and other means that temporarily seal the lid onto the container by pressing hot heat on some spots of the lid. However, this embodiment also has a number of problems to be solved. They are as follows. In the lid sterilizing process, the lid holder's capacity is limited to holding only one shape of lid. Thus, when a different shape of lid is supplied, all of the lid holders have to be replaced by another type. Moreover, when replacing the lid holders, the non-germ atmosphere may be disrupted. Both replacing the lid holders and recreating the non-germ atmosphere take time and money. Since a part of the endless chain takes place outside of the apparatus, maintaining a non-germ atmosphere is extremely difficult. Preventing hydrogen peroxide gas, which is used for sterilization, from entering into the non-germ atmosphere is also difficult. To prevent the disruption of the non-germ atmosphere, it is necessary to keep the pressure of the passage that connects the outside, the sterilizing room and the non-germ atmosphere room, higher than outside to prevent the outside air from flowing to the inside. Also it is necessary to prevent the hydrogen peroxide gas from entering into the non-germ atmosphere room or leaking to the outside. At the same time, keeping the hydrogen peroxide gas in the sterilizing room for a certain period of time is essential to adequately sterilize the lid. Unfortunately, all of these requirements cannot well be accomplished by the prior art. Since the hydrogen peroxide gas cannot be kept in the room for longer than a certain period of time, density of the gas is required to be up to about 50 percent for instance. As a result, the gas could remain on the lid and the food could be deteriorated. Since the lid holder does not possess the ability to move, means that can move the lid from one place to another is included. As a result, the structure of the apparatus is more complicated and moreover correct positioning of the lid on the container is difficult to achieve. It is possible to include means that correct the lid's position, but this makes the structure of the apparatus complicated and costly. While the lid is held by the holder, the sterilizing and the drying processes are carried out. Therefore, at least part of the lid is held and thus hidden by the holder so that it cannot be adequately sterilized or dried. The means for correcting the lid's position and for sealing the lid temporarily are mechanically connected. Thus, when a differently shaped lid is supplied, the means has to be adjusted by hand. While adjusting, therefore, the non-germ atmosphere will be disrupted. It takes time and work to recreate the non-germ atmosphere. The first object of the present invention, therefore, is to provide means that accomplishes the sterilization of the lid in a completely sealed room with its entrance and exit passages arranged to close the room. Another object is to present an apparatus that can handle differently shaped lids without changing any parts. Another object of the invention is to supply a lid on the right place of the container. Another object is to completely sterilize the whole surface of the lid. Another object is to eliminate the need for providing in the apparatus a means for correcting the lid's position relative to the container. The object is achieved by the features in the characterizing part of claim 1 as to the method and by the features of claim 3 as to the sterilization means. Fig. 1 is an elevational view of the machine for fill-and-pack in a non-germ atmosphere according to the present invention, in which means for lid sterilization and temporal sealing are included. Fig. 2 is a elevational view, partly in section, of a preferred embodiment of a lid sterilization means according to the present invention. Fig. 3 is a sectional side elevational view of the embodiment shown in Fig. 2. Fig. 4 is a elevational view in section of an outer cylinder 1 shown in Fig. 2. Fig. 5 is a side elevational view of the outer cylinder 1 shown in Fig. 4. Fig. 6 is an elevational view in section of a rotary drum 3 shown in Fig. 2. Fig. 7 is a side elevational view in section of the rotary drum 3 shown in Fig. 6. Fig. 8 is a rear elevational view of a vacuum manifold 43 shown in Fig. 3. Fig. 9 is a elevational view of a vacuum disk 44 shown in Fig. 3. Fig. 10 is a side eleavational view in section of an upper portion of the vacuum manifold 43 and the vacuum disk 44 fit together. Fig. 11 is a development drawing that shows the movement of the sucking disks 38, 42. The details of the present invention will be explained below referring to the drawings. Figure 1 shows a fill-and-pack in a non-germ atmosphere machine according to the present invention. The machine is composed of a container sterilization unit 104 and a fill-and-pack unit 110. The container sterilization unit 104 is composed of a sealed framework 113 (non-germ chamber) positioned on the supporting framework 115. In the sealed framework 113, the container supplier 105, the sterilizer dispatching mouth 106, the ultraviolet ray applying means 107, the hot wind blow duct 108 and the hot wind sucking duct 109 are positioned. At least a pair of rails is installed in the sealed framework 113 and containers 5 are hung at their flanges by the rail. The endless chain is installed to move intermittetly under the rail and pushing plates are secured to the endless chain at intervals corresponding to the intermittent motion. Each pushing plate pushes a container 5 hung on the rail freely and sends it forward. Each container 5 is first sterilized with such a sterilized agent as hydrogen peroxide applied through the sterilizer apply mouth 12, and ultraviolet rays are applied from the ultraviolet ray applier 51 (see Fig.2). after which the container 5 is completely dried by hot wind. After the sterilization is completed, the container 5 is sent to the fill-and-pack unit 110. The fill-and-pack unit 110 comprises a shut framework 114 (sealed non-germ chamber) on the supporting framework 115. In the shut framework 114, the filling means 111, the lid sterilization means 101 and the press seal means are installed. In the same shut framework 114, the temporal sealing means 102, the first positioning means (not shown in the drawings) that corrects the position of each container 5 where a lid 8 is provided for each container, and the second positioning means (not shown in the drawings) that corrects the position of each container and supports the container's flange 6 from underneath where it is pressed by the press seal means 112 for a complete sealing, are also installed. Each container 5 sent from the container sterilization unit 104 is carried intermittently in the fill-and-pack unit 110 with its flange 6 hung on the rail 7 until it arrives underneath the filling means 111. There the container is filled with food. Then the container 5 with the food filled therein is again carried underneath the lid sterilization means 101. After the container's position is adjusted by the first positioning means, a lid 8 is provided on the top of the container 5 from the lid sterilization means 101 and the lid 8 is partially sealed on the top of the container 5 by the temporal sealing means 102. Then the container 5 with the lid 8 on the top is sent beneath the press seal means 112. After the container's position is corrected by the second positioning means, the lid 8 is pressed by the press seal means 112, completing the seal of the container. The container 5 is then sent outside of the sealed framework 113. As shown in Figures 2 through 11, the lid sterilization means 101, a part of the present invention, is composed of the outer cylinder 1 which is secured by the bracket 18 to the frame wall 116 of the sealed framework 113, and the rotary drum 3 which is rotatably installed to the outer cylinder 1. The outer cylinder 1, as shown especially in Figures 4 and 5, comprises the wall cylinder 10, the inside surface of which is smooth, and the side wall 17 that closes both sides of the openings of the wall cylinder 10. The wall cylinder 10 has a carry-in mouth 11 for carrying the lid 8 in, a sterilizer apply mouth 12, an ultraviolet ray apply mouth 13, a hot wind passage mouth 14, and a carry-out mouth 15 for carrying out the sterilized lid 8. As especially clearly shown in Figures 6 and 7, the rotary drum 3, which rotates intermittently by regular angular amounts of, is composed of the cylindrically shaped main drum 30, an outer surface of which touches closely the inner surface of the cylindrically shaped wall cylinder 10, rooms 31 spaced by similar regular angular amounts on the outer surface of the main drum 30, the side plates 32 that close both opening sides of the main drum 30, the second sucking disk 42 which is firmly fixed on the bottom of the room 31 (see Fig. 2), and the first sucking disk 38 (see also Fig. 2) which can move upwardly and downwardly through the bottom wall of the room 31. The shape of the carry-in mouth 11 is arranged similar to that of the room 31. A lid 8 is provided to the right position from the lid supply means 103 into the room 31 through the carry-in mouth 11. When the room 31 revolves and stops by the carry-in mouth 11, the move arm 81 moves and the vacuum pat 82 holds the bottom lid 8 stocked in the lid magazine 80. The move arm 81 moves into the room 31 and provides the lid 8 to the second sucking disk 42. A room 31 is located between the carry-in mouth 11 and the sterilizer apply mouth 12, so that, the inside of the lid sterilization means 101 is successfully shut from the outside. The sterilizer apply mouth 12 and the ultraviolet rays apply mouth 13 are positioned near each other to continuously complete sterilization and application of ultraviolet rays. Another room 31 is located between the ultraviolet rays apply mouth 13 and the hot wind passage mouth 14 to prevent the sterilization agent from leaking into the hot wind passage mouth 14. The hot wind passage mouth 14 is interconnected with four rooms 31. Hot wind blows through all these four rooms 31, thus the lids 8 can well be dried. The partial wall 16 is provided at about the middle of the hot wind passage mouth 14 to fully apply hot wind to the back side of the lid 8. The carry-out mouth 15 is positioned next to the hot wind passage mouth 14. There is no blocking element between them. Therefore, the first sucking disk 38 with the lid 8 can move outward (in the downward direction at this position) and provide the lid 8 on the top of the container 5. At least one room 31 is located between the carry-out mouth 15 and the carry-in mouth 11 to block the passage between them. The sterilizer apply duct 50 is installed to the sterilizer apply mouth 12, and the ultraviolet rays applier 51 is installed with the shade cover 52 to the ultraviolet rays apply mouth 13. The hot wind passage mouth 14 is sealed by the cover plate 55. The hot wind supply duct 53 is installed at one side of the cover plate 55 and the hot wind exhaust duct 54 is installed at the other side of the cover plate 55. Hot wind, supplied from the hot wind supply duct 53, blows through each room 31 and is exhausted from the hot wind exhaust duct 54. As shown especially in Figure 3, the bearing boss 19 and the bearing 20 are installed to the frame wall 116 by the bracket 18. They organize the central element of parts such as the rotary drum 3, the cam plate 46 and the vacuum disk 44. The rotary drum 3, firmly secured to the rotary shaft sleeve 33 which is installed to the bearing boss 19, rotates intermittenly with force transmitted through the drive shaft 36, the drive gear 35 and the follower gear 34. The cam plate 46 and the vacuum disk 44 are fixed to the cam driving shaft 47 which is rotatably installed into the rotary shaft sleeve 33. The cam plate 46 forces the first sucking disk 38 to move upwardly and downwardly. The vacuum disk 44 interconnects and disconnects the vacuum chamber (not shown) to both first sucking disk 38 and the second sucking disk 42. The cam plate 46 and the vacuum disk 44 rotate in one direction and in the return direction together when the rotary arm 48 is driven by the up-down shaft 49. The first sucking disk 38 is installed on top of the pickup rod 39 airtightly and moveably upward and downward, the pickup rod passing through the main drum 30. The spring 40 is installed to the pickup rod 39, one side of which touches the cam wheel 41 and the other to the main drum 30. The cam wheel 41 is caused to touch the cam plate's 46 surface by the elasticity of the spring 40. The vacuum manifold 43, placed airtightly, touches the vacuum disk 44, and is firmly secured to the side plate 32. The interconnection between the sucking disks 38,42 and the vacuum chamber (not shown in the drawings) is accomplished by the mutual rotation of the vacuum manifold 43 and the vacuum disk 44. As shown in Figures 8 and 10, the vacuum manifold 43 has a number of vacuum passages 45, facing toward the side plate 32, equivalent to the number of the rooms 31. Each vacuum passage 45 includes a V-shaped second passage 45b and a first passage 45a in the center of the second passage 45b. Both of the passages 45a,45b reach the other side of the vacuum manifold 43 through the first pass hole 45c and the second pass hole 45d. The vacuum disk 44, as shown in Figures 9 and 10, has the first bypass 44a and the first opening 44c, both connected to the first passage 45a, and the second bypass 44b and the second opening 44d, both connected to the second pass hole 45d. As the vacuum disk 44 and the vacuum manifold 43 mutually rotate, interconnection and disconnection of the first passage 45a, the first bypass 44a and the first opening 44c can be accomplished. Also, as the vacuum disk 44 and the vacuum manifold 43 mutually rotate, interconnection and disconnection of the second passage 45b, the second bypass 44b and the second opening 44d can be completed. Therefore interconnection and disconnection between the sucking disks 38,42 and the vacuum chamber can mechanically be achieved. Figure 11 shows the movement of the lid sterilization means 101. When a room 31 comes by the carry-in mouth 11 (position I), the first sucking disk moves back by elastic force of the spring 40 and as the cam wheel 41 follows the cam plate, and the lid 8 is sucked and held by the second sucking disk 42. While room 31 is in the position I, the vacuum disk 44 rotates in one direction with the cam plate since both are mechanically connected to the cam driving shaft 47. And when the first sucking disk 38 is at the backing position, the first passage 45a which is a passage for the first sucking disk 38 is disconnected from the first bypass 44a, and the second passage 45b is interconnected with the second bypass 44b which is a passage for the second sucking disk 42. Thus, the lid 8 at this position can be held by the second sucking disk 42 and not by the first sucking disk 38. The room 31 then revolves and comes by the sterilizer apply mouth 12 (position II), where the sterilizer is applied to the room 31 through the sterilizer apply duct 50 and the lid 8 is sterilized. While the room 31 is at position II, the lid 8 is first held by the second sucking disk 42 and then by the first sucking disk 38 as the cam plate 46 and the vacuum disk 44 rotate in the return direction together. Therefore, the whole surface of the lid 8 can be exposed and sterilized. The room 31 then moves up by the ultraviolet rays apply mouth 13 (position III) where the lid 8 is also held alternatively by the first sucking disk 38 and by the second sucking disk, so the whole surface of the lid 8 can be sterilized by the ultraviolet rays. After the sterilization is done, the room 31 moves by the hot wind passage mouth 14, the drying zone (position IV), and there the lid 8 is completely dried. During the drying process, the lid 8 is first held by the second sucking disk 42 and then by the first sucking disk 38, so the whole surface of the lid 8 can be exposed and dried well. When the room 31 comes by the carry-out mouth 15, the first sucking disk 38 moves upwardly to the downward direction and provides the lid 8 on top of the container 5. Providing the lid 8 by the first sucking disk 38 at its center and not by the second sucking disk 42 at its edge is advantageous when the lid 8 is temporarily sealed at the next procedure. The remarkable effects of the present invention are as follows. Since each room 31 in the lid sterilization means 101 is air tightly segregated from other rooms 31 and from the outside, the outside air, which contains germs, does not enter into the room 31 and the sterilizer does not leak. A lid 8 is held by the sucking disk 38,42 in the room 31, so that any size of a lid 8 can be held by the same sucking disk 38,42. It is advantageous because the sucking disk does not have to be replaced by another one when a different sized lid 8 is to be sealed, and therefore the non-germ atmosphere can be maintained. As a result, a lot of time and work can be saved. During the sterilization process, a lid 8 is held by the first sucking disk 38 and the second sucking disk 42 at different parts. Thus, the whole surface of the lid 8 is exposed and the whole surface can be sterilized. Since a cylindrically shaped drum is used as a main element of the lid sterilization means 101, the intermittent movement can rather easily be achieved compared, for example, to a non-drum element. Therefore, it is possible to make the means simpler and more compact. The first sucking disk 38 works during the sterilization process and drying process as a lid holder. It also works as a lid provider. Since the first sucking disk 38 is applicable to the both, it is not neccessary to install another means as a lid provider. This also makes the apparatus simpler and more compact. Moreover, since the lid 8 is held only by both sucking disks 38,42 and not by another element, the position of the lid 8 on the container 5 can be kept correctly. Therefore, another means that adjusts the position of the lid 8 on the container 5 is unneccessary. Since interconnection and disconnection of the sucking disks 38,42 and the vacuum chamber is done by the rotational movement of the vacuum disk 44 ,which rotation is the same as that of the cam plate 46, the sucking procedure of the sucking disks 38,42 can be accomplished.

Claims: A method for sterilizing a seal-like lid (8) and thereafter providing said lid on top of a container (5), the container having been previously sterilized, in a non-germ atmosphere, characterized by intermittently rotating a rotary drum (3) such that it moves to successive stop positions, the rotary drum having a plurality of rooms (31), each of which has an opening that intermittently and airtightly faces an inner surface of a wall cylinder (10) having at least one mouth (11-15), and, through each mouth of said wall cylinder, (a) providing a lid (8) into one of said rooms (31), (b) applying a sterilizer and ultraviolet rays into the room to sterilize said lid and (c) blowing hot wind into the room to dry said lid, each of steps (a) - (c) being performed in order at different stop positions. A method as claimed in claim 1, wherein said lid (8) is held alternatively by a first sucking disk (38) and a second sucking disk (42) provided on said rotary drum (3), one of which is arranged to move upwardly and downwardly more than the other, at least while said sterilizer and ultraviolet rays are applied and hot wind is blown into the room. A lid sterilization means having an outer cylinder (1) which seals both sides of the cylindrically shaped wall cylinder (10), and a rotary drum (3) which comprises a number of concave shaped rooms (31) at fixed positions on an outer surface of said rotary drum, each room (31) airtightly facing an inner surface of said wall cylinder (10), the rotary drum being installed in said outer cylinder (1) to intermittently rotate by fixed angular amounts between stop positions, said wall cylinder (10) having, at portions adjacent where said rooms (31) intermittently stop, with a carry-in mouth (11) through which said lid (8) is carried into said room, a sterilizer apply mouth (12) to apply sterilizer means therethrough, an ultraviolet rays apply mouth (13) to apply ultraviolet rays therethrough, a hot wind passage mouth (14) for blowing hot wind therethrough and a carry-out mouth (15) to carry out said lid therethrough. A lid sterilization means as claimed in claim 3, further comprising a first sucking disk (38) and a second sucking disk (42) arranged to alternatively hold said lid (8) at different heights, said second sucking disk being secured at a fixed position, said first sucking disk being able to move up and down farther than said second sucking disk. A lid sterilization means as claimed in claims 3 and 4, wherein said hot wind passage mouth (14) is big enough to face and interconnect with a number of said rooms (31) at a stop position. A lid sterilization means as claimed in claim 4, wherein said first sucking disk (38) is arranged to move upwardly and downwardly following rotation of a cam plate (46) while said rotary drum (3) is at a stop position. A lid sterilization means as claimed in claim 3, further comprising a vacuum manifold (43) secured to said rotary drum (3), the vacuum manifold comprising a first passage (45a) for said first sucking disk (38) and a second passage (45b) for said second sucking disk (42), and a vacuum disk (44), airtightly, rotatably and coaxially secured to said vacuum manifold (43), the vacuum disk rotating intermittently by the same angular amounts as said rotary drum, the vacuum disk comprising a first bypass (44a) and a second bypass (44b) which interconnect and disconnect said first passage (45a) and second passage (45b) to a vacuum chamber.

Inventors: HANDA, TADASHI, HATANAKA, KOHICHI, MOGI, KATSUYUKI, SHIBAUCHI, YOSHITO, TANAKA, TATSUO
Applicants: SNOW BRAND MILK PRODUCTS CO., LTD., YOSHINO KOGYOSHO CO., LTD.
Application year: 1989
Main classification: B65B55
IPC codes: B65B55