GB1120858A - Door mechanism for centrifuge vacuum chamber - Google Patents

Abstract

A centrifuge vacuum chamber 24, Fig. 3, housing a rotor 44 driven from underneath by a spindle 46 is provided with a door mechanism comprising a plate 22, Figs. 1 and 3, secured over the top of the chamber and having an access hole 30 about which is disposed a sealing O-ring 34 carried by the plate, a door 10 adapted to sealingly engage the O-ring 34 and movable between closed and open positions for covering and uncovering the access hole 30 by means of racks 18, 20 which are horizontally movable and include cam ramps 60 for holding the door 10 and displacing it during initial movement of the racks 18, 20 when the door is being opened and during final movement of the racks when the door is being closed, means 106, 108 for restraining the door against horizontal movement during vertical movement, and a locking pin 74, Fig. 5c, for engaging and holding the door during its horizontal movement. The chamber 24 of the centrifuge has a heavy guard ring 40 for protection against rotor failure during operation. A liner 42 surrounds the rotor. The rotor may be supported in an upper bearing and seal assembly which may be mounted in an opening 48 in the door 10. When not in use, as shown, the opening is closed by a removable plug 50. A cover plate 52 having an opening 54 for registration with the access p hole 30 in the plate 22 is supported on spacer blocks 12, 14, 16. The racks 18, 20 are mounted at one end on wheels 66 of a diameter smaller than the height of the spacer blocks and are driven at the other end by gears 90 mounted on a common shaft 94 which may be driven automatically, or by means of a chain and sprocket drive 96, 98, 100 actuated manually by means of a knob 102. The upper ends of the cam ramps 60 in the racks 18, 20 join on to horizontal seats 64 which serve to carry support pins 62 in the side of the door 10 during horizontal movement of the door. The door is provided with holes 70 which are adapted to receive chamfered alignment dowel pins 72 projecting from the plate 22 during descent of the door towards the closed position. The locking pin 74 is carried in a recess in the side of the rack 18 and is biased outwardly by a spring 80 so that its head 76 bears against a cam surface