DOOR ARRANGEMENT
1432213 Pressure resistant door WARTSILA AB OY 31 Aug 1973 [1 Sept 1972] 41069/73 Heading F2P A door arrangement comprising a movable door 2, a stationary wall 1 and bolt devices 13 with driving means to press the door hermetically against the wall, is characterized in that the driving means of the bolt devices is connected to a motion transmitting system comprising an axially movable, double-ended secondary shaft 6 one end of which is connected by means of a toggle joint mechanism 11 to bolt devices 13 of the upper part of the door and the other end of which is connected by toggle joint mechanisms to bolt devices of the lower part of the door. As shown the driving means consists of a hand wheel 3 mounted on wall 1 and a shaft 4 rotatable by the wheel 3 and connected to gearing 5 mounted on the door, the gearing 5 being connected to the shaft 6 The latter has oppositely handed screw threads at its respective ends which engage with slides 7 so that rotation of shafts 6 moves the slides 7 towards or away from each other. The slides 7 have motion transmitting elements 10 which operate the toggle mechanisms 11 to move bolts 13 into engagement (or out of engagement) with bolt receiving holes in pieces 12 fixed to the wall 1. The ends of the bolts are tapered so that by a wedging action they force the door against the wall (Fig. 2, not shown). The shaft 6 has slight axial freedom of movement, e.g. by mounting the gearing 5 on the door with some resilience so that possible differences in the bolting forces in the upper and lower parts of the door are balanced through the shaft. There may be some clearance between the elements 10 and the toggle mechanisms so that the initial movement of the driving means can be used to bring about some additional function, e.g. the operation of a pressure balancing valve if the door is used in conjunction with an air lock. The door may be provided with flexible seals and a mechanical stop to prevent overcompression of the seals and the door is preferably mounted on arms 19 hinged to the wall at 20 and to the centre of the door at 17.