AUTOCLAVE DOOR

Abstract: A pressure vessel, preferably an autoclave for sterilizing by steam has an opening and a door which is swingable about a pivot axis to and from the opening plane for closing the opening. The door (18) is arranged to be slidable in the plane of the opening, and bolting means in the door and the opening frame are arranged to be brought into bolting engagement with each other by the sliding movement for taking up the operating pressure respectively out of engagement for making the door free before pivoting, which means that the door itself is arranged to be slidable for bolting.

Description: Autoclave door The present invention relates to an arrangement in a pressure vessel with an opening and a door which is swingable about a pivot axis to and from the opening plane for closing the opening, preferably in an autoclave for sterilizing by steam under pressure. Since long, sterilizing autoclaves have had swingable doors. When such an autoclave operates with an inner pressure on the door surface, bolting of the door in closed position by means of heavy fittings able to withstand this pressure is required. Different manually controllable, relatively complicated and heavy mechanisms have been used in the door for moving bolting pins into means provided therefor at the door opening of the autoclave. Still, handling of such an old-type autoclave has been connected with a certain risk of accidents due to the high pressure. In order to make automatic operation possible the autoclave has been made as a through autoclave in a wall with a door at the front side and at the rear side of the autoclave. A roller conveyor for the goods is arranged at the front side and another conveyor at the rear side. Sliding doors have replaced the former swingable doors. A sliding door can be made so as to operate in an automatic continuous system for handling of the goods. It can also be provided with safety means to reduce the risk of accidents caused by the inner pressure of the autoclave, i.a. the automatic handling of goods cannot be performed if the door is not correctly closed. There is however a drawback also in a sliding door. Many autoclaves have such large dimensions that it is hard, not to say impossible, to place the autoclave including the space required for moving the door from closed position to open position at the side of, below or above the autoclave so that the entire opening will be free for transport of goods. The object of the present invention is to remove the said drawback and provide an arrangement in an autoclave door which is such that when locating an autoclave in a space intended therefor no special space for the movements of the autoclave door has to be reserved at the side of the autoclave opening and in its plane. The invention is for this purpose mainly characterized in that the door is arranged to be slidable in the plane of the opening, bolting means in the door and the opening frame being arranged to be brought into bolting engagement with each other by the sliding movement for taking up the operating pressure respectively out of engagement for making the door free before pivoting, which means that the door itself is arranged to be slidable for bolting. ' -l In the following the invention will be described by way of example with reference to an autoclave shown in the drawings. Fig. 1 is a front view of the autoclave with a part of the door front metal sheet cut away. Fig. 2 is a portion of the autoclave of Fig. 1 seen from the right-hand side, Figs. 3 - 5 show in a horizontal section the bolting or locking means and their function. Fig. 6 is a horizontal section with control means. The autoclave shown in the Figures has large dimensions and is mounted on legs 10 adjustable in height. The chamber of the autoclave is marked in dashed lines 11. The chamber floor 12 is situated higher than the floor in the space where the autoclave is mounted. The autoclave has an upper holder 13 and a lower holder 14 for bearings 15, 16 for a pivot axis 17 carrying the autoclave door 18. The pivot axis 17 has an upper arm 19 in the shape of a rail 20, more or less quadratic in section and with a lower opening. Through this opening two carriers 21 pass from the upper edge of the door, and these carriers 21 have two rolls 22 operating in the rail 20 and making the door 18 movable in the length direction of the arm 19. For pivoting the door a driving means shown in Fig. 2 is provided which " comprises a motor 23 with a gear 24 and a sprocket 25 containing a friction coupling. A chain 26 driven by the sprocket 25 goes over a sprocket 27 connected to the axis 17. In Figs. 3 - 5 the door 18 is shown in closed position, in an intermediate position and closed but not bolted. From these Figures the principle of the bolting of the door appears. The vertical door side close to the pivot axis has several inwardly extending bolting irons 28 with holes 29. These holes are shaped so that at the movement of the door from the open position of Fig. 5 to the closed position of Fig. 3 they will slide in the direction to the pivot axis over pins 30 on bars 31 at the shell 32 of the autoclave or its frame. The pivot axis 17 also carries a guiding pin 33 which is concentric with the lowest bolting pin 30 and is intended to enter the lowest hole 29 in the bolting iron 28 in order to secure the door to the pillar forming the pivot axis 17 during the pivot movement. At the opposite, vertical side 34, which is parallel to the pivot axis 17, the door has pins 35 directed from the pivot axis 17 and shaped so that at the movement of the door from the pivot axis 17 they will enter holes 36 in clamps 37 arranged at the frame of the autoclave. The clamp 37 and the bolting iron 28 have adjusting screws 37a. With these the engagement between the bolting means can be set and also adjusted, if it should be desirable. Exteriorly, the door has a front metal sheet 38 which at the side beside the pivot axis and at the opposite side has a larger extension than the frame of the door. . As appears from Figs. 1 and 3 - 5 the autoclave front has a groove 39 around the opening with a sealing strip 40 known per se. It can be formed by a rubber hose which is inflatable by means of a pressure medium, for instance steam. On a cross bar 41 in the centre of the door a cylinder 42 is attached and on the pivot axis 17 a piston rod 43 is attached carrying a double-acting piston 44 operating in the cylinder 42. ' Fig. 6 is a very schematic horizontal section through a through autoclave with a door 18 at the front side as well as at the rear side. The two doors operate in the same way and thus the description thereof can be limited to the front door. A pressure medium, for instance steam, is supplied to a conduit 45 according to the arrow 46. Through a conduit 47 connected to the conduit 45 and having a magnet valve 48 and a manual valve 49, which is normally open, steam can be supplied to the room 50 of the cylinder 42 at the left side of the piston 44. Then the door is pressed in the direction to the bolted position shown in full lines in Fig. 6. Thereafter steam is supplied through a conduit 51 with a magnet valve 52 to the groove 39 around the door opening. The sealing 40 in the groove can be arranged either so that it is inflated by a pressure medium and presses against the door inner side or either so that the pressure in the groove 39 presses the sealing against the door. The conduit 51 after the valve 52 has a branch conduit 53 to a groove 54 at the rear side of the autoclave to provide a door sealing at both sides at the same time. After finished sterilizing the sealing pressure in the groove 39 is released by a magnet valve 59 being opened in a conduit 60 to a suction means, not shown, for instance a vacuum pump or an ejector, the sealing 40 being sucked into its groove 39 or 54. A magnet valve 55 in a branch conduit 56 in the compressed-air system is opened and compressed air is pressed into the room 57 of the cylinder 42 to the right of the piston 44. Thereby the door 18 is moved to the right out of engagement with the bolts and thereafter by the motor 23 it can be swung out entirely so that the autoclave chamber will be available. When the door is moved to the right it is brought to the position 58 shown in dashed lines. At the hinge side edge of the door 17 there are means 61 which when the door is moved are intended to act on two switches 62, 63. Further the pivot axis has means 64 adjusted at the pivoting movement to act on a switch 65. The autoclave has automatically operating control means with which at least one sterilizing program can be performed automatically in the autoclave. In order for a program to be started it is required that the door is in closed position so that the switch 65 is inactive and that the door is moved to bolting position so that the switch 62 is not acted upon. Only when the switch 63 is acted upon by the door the pivoting means can operate. The valve 49 is a safety device. By this the compressed air supply can be switched off during servicing work in the chamber. Persons working inside the chamber can be sure that the door cannot be moved. The autoclave as shown and described has legs and a horizontally swingable door. If it is desired to have the chamber floor level with the room floor the door can be made to move up and down and to be swingable in the raised position. In the floor, a slot is made ahead of the chamber in which the lower edge of the door Is inserted. This slot can be covered by a rail which is pressed to the floor level by springs. Locking means for the rail make it possible to roll trucks with goods over the rail.

Claims: Claims 1. Arrangement in a pressure vessel with an opening and a door which i swingable about a pivot axis to and from the opening plane for closing th opening, preferably in an autoclave for sterilizing by steam under pressure characterized in that the door (18) is arranged to be slidable in the plan of the opening, bolting means in the door and the opening frame being arranged t be brought into bolting engagement with each other by the sliding movement fo taking up the operating pressure respectively out of engagement for making the door free before pivoting, which means that the door itself is arranged to be slidable for bolting. 2. Arrangement according to Claim 1, characterized in that the door (18) is horizontally slidable and mounted to be swingable about a vertical axis (17). 3. Arrangement according to Claim 1, characterized in that the door (18) has means (28,29,35) by which it engages means (30,36,37) on the frame of the vessel at two parallel opening edges transversal to the sliding direction of the door. 4. Arrangement according to Claim 1, characterized in that the four sides of the door (18) have bolting means. 5. Arrangement according to Claim 1, characterized in that a motor (23) with gear (24) and transmission means (25,26,27) is arranged to swing the door (18). 6. Arrangement according to Claim 2, characterized in that a cylinder (42) with piston (44) is arranged to perform the sliding movement of the door (18) by a pressure medium, preferably compressed air. 7. Arrangement according to Claim 3, characterized in that the vessel at the opening on the hinge side has pins (30) directed to the hinge and the door (18) corresponding bolting irons (28) with holes (29) for the pins (30) and that the vessel at an opposite parallel side has protruding clamps (37) with holes (36) adjusted for pins (35) directed away from the hinges from the frame of the door (18). 8. Arrangement according to Claim 2, characterized in that the pivot axis (17) of the door (18) is mounted on the vessel and connected to at least one guiding rail (20) on which the door is slidably arranged in rolls (22) or the like. 9. Arrangement according to any of Claims 1- 8, characterized . in that the means of the door (18) for swinging and its means for sliding have locking means (62,65) which prevent swinging of the door (18) when moved from the pivot axis (17) respectively prevents sliding from the axis (17) with the door (18) swung from the closing position.

Inventors: MATTSSON HANS OLLE, MATTSSON, HANS, OLLE
Applicants: ELECTROLUX AB, AKTIEBOLAGET ELECTROLUX
Application year: 1982
Main classification: A61L2
IPC codes: A61L2, B01J3, F16J13