US 3889421 A
A door arrangement which comprises a movable door of basically rectangular form, a stationary wall and a bolt device comprising movable bolts in the door and a bolt receiving member at the wall. The bolt device includes a driving means for moving the bolts and pressing the door hermetically against the wall. The driving means comprises a driving member connected to a motion transmission system having an axially slightly movable through-going two-ended secondary shaft, one end of which is connected by means of a toggle joint mechanism to the bolt device so as to move the bolts of the upper part of the door, and the other end of which is likewise connected by means of a toggle joint mechanism to the bolt device of the lower part of the door. The bolting forces of the upper part and the lower part of the door, respectively, balance each other so that the whole door is pressed with the same force at all parts against the wall.
Claims available in
Description (OCR text may contain errors)
United States Patent [1 1 Ahonen June 17, 1975 Aarre Ahonen, Lahderanta, Finland  Foreign Application Priority Data Sept. I, I972 Finland 24l I172 [52} U.S. Cl. 49/395; 292/39; 292/42 [5 I] Int. Cl. EOSC 9/00  Field of Search 49/395, 253, 362; 292/39,
 References Cited UNITED STATES PATENTS l2/l943 Vani 49/253 X 2,373,480 4/1945 Lambert 49/395 X 3,022,065 2/1962 Martin 49/362 FOREIGN PATENTS OR APPLICATIONS 49,505 1/1939 France 292/43 Primary Examiner-Kenneth Downey Attorney, Agent, or Firm-Haseltine, Lake & Waters I57] ABSTRACT A door arrangement which comprises a movable door of basically rectangular form, a stationary wall and a bolt device comprising movable bolts in the door and a bolt receiving member at the wall. The bolt device includes a driving means for moving the bolts and pressing the door hermetically against the wall. The driving means comprises a driving member connected to a motion transmission system having an axially slightly movable through-going two-ended secondary shaft, one end of which is connected by means of a toggle joint mechanism to the bolt device so as to move the bolts of the upper part of the door, and the other end of which is likewise connected by means of a toggle joint mechanism to the bolt device of the lower part of the door. The bolting forces of the upper part and the lower part of the door, respectively, balance each other so that the whole door is pressed with the same force at all parts against the wall.
5 Claims, 3 Drawing Figures PATENTEDJUN 1 1 ms 3 889 ',421
sum 2 FIG.2
DOOR ARRANGEMENT The invention relates to a door arrangement comprising a movable door, a stationary wall and a bolt device with driving means to press the door hermetically against the wall.
Air tight doors are needed for the most different purposes. Especially in the field of nuclear engineering the use of hermetic doors and air locks equipped with such doors to isolate dangerous areas completely from the surroundings. has recently increased. Hermetic doors used in different nuclear plants, must come up to very high standards. The door must be absolutely tight even when subject to high pressure and high temperature. Due to these requirements the doors are very expensive and complicated. In addition to this, it has usually been necessary to design the door arrangement individually for each case, because the bolt devices of the doors have usually been located on the wall surrounding the door, where the available space may vary very much, in size as well as in shape. This too has been a factor contributing in making the manufacturing costs of the door unduly high.
The object of the invention is to provide a door arrangement wherein said disadvantages have been eliminated, which arrangement is especially suitable for the different needs of nuclear engineering. The invention is characterized in that the driving means of the bolt device comprises a driving shaft on the like, connected to a motion transmission system having an axially slightly movable, through-going two-ended secondary shaft one end of which is connected by means of a toggle joint mechanism connected to the bolt device of the upper part of the door and the other end of which is likewise connected by means of a toggle joint mechanism to the bolt device of the lower part of the door.
A door arrangement according to the invention has proved to be very advantageous as regards its constructional characteristics. Firstly, all the parts, essential for the closing and opening of the door, are located in the door itself so that the doors may easily be standardized. As the driving means of the bolt device is divided in two symmetric parts, the reaction forces into these two parts counteract each other and the bolting forces of the upper and lower parts of the door are balanced so that the whole door is pressed with the same force at all parts against the surrounding wall. This is possible because the two-ended driving shaft of the bolt devices is movable in the axial direction so that possible differences between the bolting forces in the upper and lower parts of the door are balanced through this shaft. The shaft can be axially movable in t motion transmission sleeve, or the whole motion transmission mechanism, including the shaft. can be, for instance, resiliently attached to the door. By means ofthe toggle joint mechanism the advantage is obtained that at the first stage of the opening of the door, when the needed bolting force is small. the transmission ratio of the toggle joint mechanism is small, but increases to a very high value at the final stage of the closing of the door when there is need for a great force.
The bolt devices and the hinge mechanism ofa door according to the invention are advantageously designed so that these items, quite different as they are, concur in bringing about the most advantageous construction possible. As the door usually is basically rectangular, and its height greatly exceeds its width, there are grounds for providing bolts on the long sides of the door only. Thus the whole structure of the bolt device can be made considerably simpler. The short sides of the door, however, form a weak spot, where leakages easily may occur, due to the fact that the deflection of the door caused by pressure, will be greatest in the middle of the short sides of the door. If the door is hinged by means of hinge arms turnably journalled at the surrounding wall and at the door with one end journalled in bearings at the center part of the short sides of the door, the last mentioned bearings with their support structure also form a stiffener reinforcing the weakest part of the door. Thus the door is both hinged and stiffened with the best possible result.
If there is attached to the surrounding wall a counter piece for the door bolts, protruding from the wall plane and provided with openings, this counter piece may also act as a stiffener for the wall. Thus a part originally designed for another purpose may be used as a stiffener, principally in the same way as in the hinge arrangement of the door.
The press force needed to seal the door can, in a door arrangement according to the invention, be achieved in the easiest way by providing each bolt of the door with a bevelled surface which together with the corresponding surface of the counter piece for the bolts produce a force pressing the door against the stationary wall as the bolts move outwards from the door. The angle between the longitudinal axis of the bolt and the said bevelled surface is preferably made larger than the friction angle, as it is more advantageous to lock the bolts with the toggle joint mechanism than by means of friction.
'The toggle joint may in the final stage of the closing of the door somewhat pass its dead center and in this position rest against a fixed stop.
The driving means of the toggle joint mechanism of the door is advantageously so designed that there is a substantial clearance, because this clearance may be used to bring about some additional function with the same driving means. If, for instance, the door arrangement acts as a door in an air lock, the said additional function may be the closing and opening of a pressure balancing valve at the final stage of the closing and at the beginning stage of the opening of the door. Thus no extra equipment will be needed to operate the pressure balancing valve.
The seal of a door arrangement according to the invention should preferably be resilient and there can also be several seals. One seal with several sealing edges can also be used. There are also grounds for arranging a mechanical stop for the door to keep the resilient seal from being too greatly compressed.
The invention will now be described in greaterdetail with reference to the attached drawings, wherein FIG. 1 shows a door arrangement according to the invention seen from the outside of the door,
FIG. 2 shows, partly in section, a bolt of the door and its guiding device, and
FIG. 3 shows a cross-section of the sealing arrangement of the door.
In the drawings, 1 indicates the wall whereon the door 2 is hinged. A driving means provided with a hand wheel 3 is attached to the wall 1, from which driving means a shaft 4 is connected to a gearing 5 attached in the center portion of the door. A double screw shaft 6 extends vertically through the gearing 5 and has at one end a left-hand screw thread, which, when rotating,
moves the slide 7 of the bolt device of the upper part of the door in a vertical direction. At the other end of the shaft 6 there is a right hand screw thread which correspondingly moves the slide 8 of the lower part of the door in a vertical direction. The slides 7 and 8 are guided by slide bars 9. Motion transmission elements 10 are fastened to the slides and act on toggle joint mechanisms 11 in such a way that when the slides move towards each other, the toggle joint mechanisms 11 push the bolts on the long sides of the door outwards forcing them into bolt openings in a counter piece 12 fastened to the wall 1.
In FIG. 1, the position of one toggle joint mechanism when the door is completely closed is shown with dotted lines 110. The toggle joint mechanism has then passed its dead center to a self-locking position, and is resting against a fixed stop 25.
FIG. 2 shows the bevelled surface 14 at the outer end of bolt 13 and the corresponding surface 15 in the bolt opening of the counter piece 12. The angle between the bevelled surface I4 and the longitudinal axis of the bolt is a little larger than the friction angle, i.e., about 15, which makes the toggle joint mechanism move by itself into a self-locking position in the final stage of the closing of the door.
The counter pieces 12 for the bolts 13 also act as stiffeners for the wall 1, and they are fastened to the wall by supporting pieces 16. The bearings 17 for the hinging of the door, provided in the middle of the upper and the lower parts of the door, act, together with their clearance 21. This clearance brings forth some important advantages. In the first place, the installation of the toggle joint mechanism will be easier, in the second place the toggle joint mechanism will move by itself into a self-locking position, and in the third place, the free space provided by the clearance may be used to obtain additional functions by means of the driving means of the toggle joint mechanism. The driving means may, for instance, be connected to a pressure balancing valve, which will then open and close suitably at the beginning of the opening stage and at the end of the closing stage of the door. Said clearance may, of course, also be placed somewhere else in the motion transmission system of the bolt device.
The sealing system of the door arrangement according to the invention is shown in detail in FIG. 3. Two seals 22 and 23 are provided on the door 2, the latter of which has two sealing edges that under pressure will press more tightly against the counter surface 26. The seal 23 is thus self sealing, To keep the seals from being accidentally compressed so much that they are damaged, a mechanical stop 24 is provided at the door 2.
lO ranged in two groups each forming one half of a substantially symmetrical configuration and bolt receiving members at said wall, said bolt device further including a driving means for moving said bolts and pressing said door hermetically against said wall, said driving means comprising a driving member, a motion transmission system connected to said driving member, and including an axially slightly movable through-going, twoended secondary shaft, upper and lower slides respectively connected to one of the ends of the shaft, at least one toggle joint mechanism for each slide connected at one end to the door and at the other end to a bolt of the respective group, and axially spaced drive elements on said slides engaging the joint of a respective said tog gle joint mechanism for projecting or retracting the as- 5 sociated bolt, one drive element in each pair being on one side of the joint of the associated toggle joint mechanism and the other drive element of the same pair being on the other side of the joint of the associated toggle joint mechanism, each toggle joint mechanism moving to an over-center locked position in going from the retracted to the projected position, stop means on said door for engaging each toggle joint mechanism to limit the over-center movement thereof, and guide means on said door engaging said slides for guiding the same in axial displacement.
2. A door arrangement according to claim 1, in which said bolts are at least substantially perpendicular to the longer sides of said door and further comprising a hinge mechanism turnably journalled at said wall and a door reinforcing structure connected to said hinge mechanism and to the middle portion of the shorter sides of said door.
3. A door arrangement according to claim 1, in which said bolt receiving member is provided with openings for said bolts and protrudes from the plane of said wall in the form of a wall reinforcing structural element.
4. A door arrangement according to claim 1, in which said bolts are provided with a bevelled surface which together with a corresponding surface of said bolt re- 0 closed.