[0001] The present invention relates to a linkage system in an apparatus for automatically
opening and closing at least one folding door of the kind having two door sections,
arranged foldable against each other, one door section hereinafter referred to as
the inner section being privotably attached to a wall inside of the door opening with
the aid of hinge means, the linkage system including a motor provided with an arm
on the motor drive shaft and firmly mounted on the inside of the wall above the door
opening, one end of the arm being pivotably connected to one end of a connecting rod.
[0002] Linkage systems of the kind referred to above are known and include a link pivotably
connected at one end to the arm on the motor drive shaft, its other end being pivotably
connected to a bracket fixed to the inner door section and projecting out at right
angles from it. The known system is burdened with at least two disadvantages, of which
the foremost is that the bracket encroaches on the space behind the inner door section
when the folding door is in its open position, i.e. when the door opening is fully
exposed. The bracket projecting from the opened folding door must have a free path,
this limiting the width of the door opening, or alternatively requires the provision
of openings in the side walls of the room where the door is installed. Another disadvantage
is that the torque caused by the wind load against the door leaves exerts unfavourable
loads on the door frame hinges and door leaves when the lateral space behind the inner
section bracket is small. This results in a third disadvantage appearing as a swaying
and jerky motion of the door, this being accompanied with peak loads acting on the
hinges and door attachments.
[0003] The lever arm from the door frame hinges to the pivoting point on the braket munted
on the door leaf is decisive for dimensioning hinges and leaf in realtion to wind
loading and the size of the door opening and also for dimensioning the required space
behind the inner door leaf.
[0004] The present invention has the object of providing a linkage system of the kind described
in the introduction, which avoids the disadvantages of the known configuration and
does not have any details encroaching on the space behind the inner door section in
the open position of the folding door, and wherein the force from the connecting rod
is applied at the outer door section via a linkage system.
[0005] The invention will now be described in detail below in conjunction with the accompanying
drawings, on which
Fig. 1 is a plan view seen from above of a known structure for automatically opening
and closing a folding door,
Fig. 2 is a plan view from above of a structure for automatically opening and closing
a folding door in accordance with the present invention and
Fig. 3 is a side view of the structure shown in Fig. 2.
[0006] Fig. 1 illustrates a known structure for automatically opening and closing a folding
door of the kind having two door sections 1, 2 which are foldable against each other.
The section 1 is designated "outer section" and section 2 "inner section" or door
frame section. The folding door is suspended in the door opening 3 with the aid of
hinge means 4. A bracket 5 is attached to the upper portion of the inner door section
2. The bracket has the form of a rectangular bar, the outer end of which is pivotably
attached to a connecting rod 6, the opposite end of which is in turn pivotably connected
to an arm 7 rotated by the output shaft of a motor 8, which is mounted on the wall
above the door opening 3. On actuation of the motor 8 in one direction, the arm 7
is turned in the direction indicated by the arrow 9, the connecting rod 6 moving the
inner door leaf 2 from the position illustrated by full lines in Fig. 1 to the open
position illustrated by chain-dotted lines. A guide roller, not shown, is mounted
on the upper portion of the outer door section 1, and a guide rail, not shown, is
mounted on the wall above the door opening 3 and cooperates with the guide roller
to guide the outer door leaf during the opening movement from the closed position
illustrated in Fig. 1 by full lines to the open position illustrated by chain-dotted
lines.
[0007] It will be seen from Fig. 1 that the bracket 5 encroaches on the space behind the
door blade in the open position of the door, which is a disadvantage, particularly
if it is necessary to cut a hole or an opening (illustrated by dashed lines in Fig.
1) in the side wall 10 of the room to which the door opens. It is sometimes impossible
to carry out such cutting and it will then be necessary to mount the hinges 4 so far
out from the side wall 10 that the available door opening width is reduced.
[0008] Although not previously mentioned, there is a hinge means 12 joining door sections
I and 2 to each other. If the door opening iswide, two folding doors can be arranged
in line as indicated in Fig. 1, where only the corresponding outer door section 13
for the additional folding door has been indicated. It will be further noted that
the additional section can be operated by the same motor 8, which is used for operating
the door sections described in the introduction, an additional arm 14 on the motor
drive shaft being pivotably connected to an additional connecting rod 15, which is
in turn pivotably connected to a bracket, not shown, mounted at the top section of
the inner door leaf, not shown, of the additional folding door.
[0009] Fig. 2 illustrates a new linkage system in accordance with the present invention.
Details in Fig. 2 and 3 corresponding to those in Fig. 1 are denoted by the same reference
characters. A motor 8 is mounted on the wall 16 about the door opening 3 on a motor
bracket 17. The motor has a driving arm 7, which is pivotably connected at its outer
end to a connecting rod 6, the other end of which is pivotably connected to the substantially
perpendicular leg 19 of a T-shaped lever 25. The pivoting point between members 6
and 19 is denoted by 20. The pivoting point between members 7 and 6 is denoted by
21. A bracket 22 is attached to the upper edge of the outer door section 1, and has
a triangular configuration (see Fig. 2) with a pivoting point 23 at its apex, to which
one end of a link 24 is pivotably connected. The other end of this link is pivotably
connected at a pivoting point 26' to the lever 25. The other end of the lever 25 is
pivotably connected to a wall bracket 26 which, similarly to the motor bracket 17
is attached to the wall 16 above the door opening 3. The leg 19 is rigidly attached,
e.g. welded, to the lever 25. The pivoting point between the wall bracket 26 and the
lever 25 is denoted by 27. Distinguishing from the previously known structure the
action of the connecting rod 6 is translated via the leg 19 (pivoting point 20) and
lever 25 (pivoting point or fulcrum 27) to the door bracket 22. The point of action
is thus moved further away from the hinge 4 to the region of the outer section 1.
This considerably increases the lever arm to the hinging point 4, which results in
a more favorable force distribution to door frame hinges and door leaf.
[0010] By the mentioned disposition of the door bracket 22 there is also afforded the possibility
of not encroaching the space behind the opened folding door, i.e. the space between
the side wall 10 and the inner door section 2 when the latter is in the position illustrated
by chain-dotted lines in Fig. 2. It will be understood that the length of the leg
19 must not be made so great that its end thrusts out past the opened door leaf 2
if the feature with the free space behind the door blade 2 is to be retained.
[0011] In the illustrated example the combined width of the door levers 1 and 2 is 1.95
m, the distance between the hinging point 4 and the pivoting point 27 is 0.4 m and
the lever arm between the pivoting points 27 and 20 is 0.52. It will be understood
that said extended lever arm between the door hinging point 4 and the door bracket
22 is dependent on the combined width of the door leafes. The greater this combined
width is, the farther away the door bracket 22 must be moved from the hinging point.
[0012] In Fig. 2 the positions of the door sections 1 and 2 are illustrated by chain-dotted
lines when the folding door is open. During the movement of the door from the closed
to the opened position the lever 25 moves through an arc round its fulcrum 27 while
the inner door section 2 moves in an arc round the hinging point 4. The link 24 pivots
about 220° clockwise from the position illustrated in Fig. 1 and the driving arm 7
moves thorugh an angle of about 180° clockwise from the position illustrated by full
lines in Fig. 1. During the opening movement the pivoting point 23 first describes
a cycloidal movement from the position illustrated in Fig. 1 by full lines, and during
the last third of the opening movement this point moves substantially at right angles
to the side wall 10, i.e. substantially parallel to the door opening. The link 24
takes up the relative motion between the arcuate movement of pivoting point 26' and
the motion of the pivoting point 23. A conventional guide rail 28, mounted in the
wall portion 16 above the door opening with the aid of a plurality of stays 29 guides
the front edge of the outer door section, assisted by a conventional guiding roller
30 arranged in the configuration with the mentioned front edge.
[0013] The length of the connection rod 6 is conventionally adjustable with the aid of a
bar 31 telescopically inserted in the rod 6, and the position of the bar can be locked
with the aid of a conventional emergency opener 32, which can be used if there is
a current failure to the motor or if the motor fails for some other reasons, and it
is desired to open or close the door. The length of the connecting rod 6 is dependent
on the positioning of the motor 8 relative to the central opening of the door, which
is denoted by the chain-dotted line C
L.
[0014] If so desired, the motor 8 can be provided with an additional driving arm 7 which,
in a way corresponding to the structure according to Fig. 1, is caused to operate
the other folding door half in the case where it is desired to have both folding door
halves operated simultaneously.
[0015] The embodiment of the invention described above can be varied in may ways and modified
within the scope of the inventive concept.
1. A linkage system in a folding door of the kind which has outer (1) and inner (2)
door sections which are foldable aginst each other, and of which the inner (2) is
pivotably attached to a wall inside of the door opening (3) with the aid of hinge
means (4), said linkage system being intended for installation between the folding
door and a wall-mounted motor (8) for opening and closing the folding door, said system
including a connecting rod (6) having one end pivotably mounted on an arm (7) on the
motor drive shaft and its other end pivotably connected at a first pivoting point
(20) on a lever (25), said lever at one end having its fulcrum at a point (27) situated
above the door opening and at a distance from the hinge means (4) and at its other
end being in force translating connection with the folding door, characterized in
that the force translating connection comprises a link (24) with one end pivotably
connected at a second pivoting point (26') to the other end of the link (25) and at
its other end being pivotably connected at a third pivoting point (23) to a door bracket
(22) mounted on the outer door section (1).
2. A linkage system as claimed in claim 1, characterized in that the connecting rod
(6) is connected to the lever (25) at a leg portion (19) rigidly attached to the lever
(25) and projecting out from it.