GB2174143A - Method and apparatus for controlling the opening/closing of a door - Google Patents

Abstract

A door (2) is linked to its frame (1) by means of a door closer (4) via arms (5, 6) which are articulated one to the other. The location of the fulcrum (11) of the remote end of the arm (6) closest to the door, is moved, relative to the door closer (4), in order to change the turning moment exerted on the door (4) by the door closer in such a way that different turning moments apply in separate phases of opening and closing of the door. In addition, for preventing opening of the door, the fulcrum (11) can be shifted such that the turning moment required to open the door is considerably increased (e.g. by aligning the arms (5, 6) one above the other). <IMAGE>

Description

SPECIFICATION Method and apparatus for controlling the opening closing of a door The invention relates to a method for controlling the force exerted by a door closer on a door and to an apparatus for putting the method into practice.

The main operation of a door closer, that is the closing of the door associated therewith, is generally based on a spring, which recloses the door after opening. The door closer is generally mounted on the door frame, although mounting on the door is also possible, and the door-closing force is transmitted from the door closer to the door by means of arms, which are pivotally connected adjacent respective one ends of the two arms, to each other and from adjacent the other end of one arm to the door closer and from adjacent the other end of the other arm to the door.

Hence, in practice the transmission of the doorclosing (e.g. spring) force takes place in the form of a turning moment of an articulated arm assembly mounted on a turnable shaft of the door closer.

Door closers typically also include a pressure fluid which, during the closing operation of the door resists the force of the door-closing force, slowing down the movement of the door and, hence, ensuring that the door will not close too rapidly. On the other hand, during an opening movement of the door, the internal arrangements of the door closer are adjusted so that the pressure fluid causes a little resistance as possible, to the opening movement of the door. Even with these arrangements, the door is rather "heavy" in the initial phase of its opening movement, due to the internal construction of the door closer, the spring, and frictional forces, which cause a turning moment that resists the opening of the door, and due to the position of the arms of the articulated assembly relative to each other.

United States Patent Specification 4,419,786 discloses an arrangement for reducing the force needed for opening a door which is provided with a door closer. According to this prior art disclosure, the remote end of the arm assembly of the door closer is displaced in a guiding track during a certain phase of the opening movement of the door by making use of spring forces and a hydraulic or pneumatic control system. Thus the turning moment exerted by the door closer on the door, via the articulated arm assembly, will be changed during the door opening movement The principle of operation diclosed in US 4,419,786 is feasible, but nevertheless the construction proposed for this prior art arrangement is somewhat complicated and its adaptability to the different conditions likely to be met in practice, is not felt to be adequate.

One aim of the present invention is to provide an improved and more versatile solution to the problems described above, so that the opening of the door can be accomplished by means of a lighter force than previously required without affecting secure and reliable closing of the door. A further aim of the present invention is to provide apparatus which permits a door closer also to be used for looking the door in its closed position and in which the control provided for these various opera.;ons is provided in an uncomplicated and reliable manner.

What constitutes the invention in its method aspect is defined in the following claim 1 and in its apparatus aspect in the following claim 7.

Thus, in accordance with the invention by shifting the fulcrum connection of the remote end, relative to the door closer, of the articulated arm assembly, the turning moment exerted on the door by the door closer is changed in separate phases of the opening and closing movements of the door and, if required, also when the door is fully closed.

This can be accomplished without affecting the door closer itself or changing its internal construction in any way.

Thus, by virtue of the invention, the opening of the door can be made lighter in a simple manner, by decreasing the resisting moment exerted on the door. For a closing movement of the door, the turning moment exerted on the door is respectively increased to its maximum value. Thus, depending on the chosen location of the door closer, a door closer of sufficient strength can be selected for securing closing of the door for example in windy locations, without any risk of the door becoming unreasonably "heavy" in its opening phase. In addition, when the door is completely closed, a door closer apparatus according to the invention can, with advantage, be used to prevent opening of the door by shifting the fulcrum connection of the articulated arm assembly of the door closer, so that the moment exerted on the door by the door closer is considerably increased.This arrangement can with advantage, be used, for example, for a fire door and could then ensure the door remains closed in the face of pressures generated by a fire. If the said fulcrum connection is shifted so that the angle between the arms of the articulated arm assembly decreases to an at least substantial alignment of the arms, a complete locking of the door in its closed position can be obtained by means of the door closer without using any actual, conventional locking mechanism at all. A door closer with the described features, can with advantage be incorporated as one part of a larger system, in which a, preferably programmable, central control unit simultaneously controls a plurality of doors at separate locations which require simultaneous locking.

In a practical operation of a door closer according to the invention, the shift of the fulcrum connection of the arm assembly can, with advantage, occur during the actual movement of the door, for instance when the door is ajar no more than 1 to 3D. As at that phase, the door is already nearly closed and there is no longer danger that, for instance, a sudden gust of wind will move the door, the decrease of the turning moment can with advantage be commenced, so that the door is already "light" when the next opening movement begins.

Correspondingly, the increases of the turning moment on opening, can with advantage be intro duced as soon as the stiffness appearing in the very initial phase of the opening of the door has been overcome, because thereafter the resisting forces are relatively considerably less. Naturally, depending on the location of the door and the purpose served by the door, the decrease and the increase of the turning moment can be timed to take place also at some other appropriate open position of the door.

The required shift of the fulcrum connection can, with advantage, in apparatus according to the invention, be arranged so that the end of the articulated arm assembly is pivotally mounted on a slide member, which is supported to be linearly movable in a guiding member mounted on the door.

The displacement of the slide member can be accomplished by means of an actuator, for instance by an electric motor.

Apparatus according to the invention can also be provided with a control unit, which energies the actuator at a desired opening position of the door and shifts the slide member to a position predetermined as being appropriate having regard to the desired change in the moment required to be exerted on the door by the door closer. In addition, when the door is fully closed, the control unit can be arranged to shift the slide member into a position providing for the aforementioned locking of the door. The control member can, with advantage, be linked to micro-switches used to determined when the slide member is in its end positions and these micro-switches can be used for controlling the operation of the actuator.

The invention will now be described, by way of example, in greater detail, with reference to the accompanying drawings, in which Figures 1 to 5 show schematicaliy the basic principles of the invention in different phases of the opening and closing of a door, Figure 6 shows schematically how the door can be locked by means of an arrangement according to the invention, Figures 7a and 7b show a sectional view and an upper view, respectively, of one arrangement for putting the method according to the invention into practice, Figure 8 shows schematically the principles for controlling an apparatus according to the invention, and Figure 9 shows one embodiment of circuit for achievirig the required control of the movement of a door.

In Figures 1 to 6 and 8, numeral 1 indicates a door frame in which a door 2 is turnably supported by means of a hinge 3. A door closer 4 is mounted on the door frame 1, and a first arm 5 is mounted on a turnable shaft 7 of the door closer 4. A second arm 6 is, on one hand articulated to the first arm 5 by means of an articulation member 8 and, on the other hand is movably connected to a guiding member 9, mounted on the door 2, by means of an articulation member 11, the fulcrum of which can be moved within a guiding track 10 of the guiding member 9.Hence, the door closer 4 acts on the door 2 through the arms 5 and 6 with a turning moment 16' (see Figures 3 to 5) about the shaft 7, the magnitude of which turning moment in each case depends on the compression of a spring (not shown) within the door closer 4 and hence on the position of the door 2 relative to its frame 1.

The arrangement is such that the direction of movement of the door, and the position and operation of the members of the door closer 4, have an effect on the true magnitude of the turning moment 16'. As distinct from this true turning moment 16', transmitted from the shaft 7 of the door closer 4, an effective turning moment 16 (also shown in Figures 3 to 5) is created, which actually affects the door, via the articulation member 11, at the position of the hinge 3.

Figure 1 shows a situation, in which the door 2 is closed in its frame 1 and the arms 5 and 6 are in positions, in which the force exerted on the door 2 by the door closer 4 to resist opening of the door is at its minimum level. This minimum force position is obtained when the articulation member 11 is at a distance "A" from the turning axis of the door (e.g. from the hinge 3). Thus, in this minimum force position, the effective turning moment 16 exerted on the door by the door closer 4, through the force transmission arms 5 and 6 and the articulation member 11, has been decreased in spite of the fact that the internal forces of the door closer 4 resisting an opening movement of the door remain unchanged. As a result, the initial phase of opening the door requires a reduced force on the door, than is needed during later phases.

Once the door has started to move towards its fully open position, which movement is shown by an arrow 12 in Figure 2, the force required to be applied to the door to continue its opening movement reduces considerably. As a result, the location of the articulation member 11 along the track 10 moves (in the direction of an arrow 13) towards a location in which the moment 16 exerted on the door through the arms 5 and 6 increases. Thus the distance of the articulation member 11 from the hinge 3 decreases, that is the distance B in Figure 2 is less than the distance A in the initial situation in Figure 1. In practice the displacement of the articulation member 11 can commence as soon as the door has opened a few (e.g. 1 to 3 ) degrees.

In the situation shown in Figure 3, the door 2 is fully open and the arms 5 and 6 are in positions, where the turning moment 16 exerted on the door therethrough is at its maximum, when the door is in the final phase of its closing movement. Thus the distance C of the articulation member 11 from the hinge 3 of the door is now at its minimum value.

In Figure 4, the door is about to close and the direction of door movement is shown by an arrow 14. The distance of the articulation member 11 from the hinge 3 is still at its minimum value of C, whereby the moment 16 exerted on the door via the articulation member 8 is as large as possible, an arrangement required to ensure a reliable closing movement of the door.

Figure 5 shows the final phase of the closing movement of the door, with the door almost closed. In this phase, there is no longer a risk that, for instance, wind might pull the door open, so the location of the fulcrum connection provided by the articulation member 11 can start to move (in the direction of arrow 15) back towards the location shown in Figure 1, where the effect of the moment 16' on the door is at a minimum. This final displacing movement can, with advantage, commence when the door is only open by a few degrees (say 3 or less) because then the members of the door closer are already in a so-called final wrench position, which is used to ensure the final closing movement of the door.By effecting this movement of the articulation member 11 at the end of the door closing movement, the door is effectively "lightened" in anticipation of the next opening movement of the door.

In a practical experiment, the maximum distance "A" between the articulation member 11 and the hinge 3 was selected to be 340 mm and the minimum distance "C" was selected to be 255 mm. It proved that, for instance, when opening the door, the force needed to be exerted on the door to open it could be reduced almost to one half by means of the arrangement according to the invention, that is by using the distance A instead of the distance C.

Hence, when the opening turning moment is normally about twice as large as the closing turning moment, by means of the arrangement according to the invention, the two turning moments can be made to have about equal magnitude.

Figure 6 shows an arrangement in accordance with the invention, in which the location of the fulcrum of the articulation member 11 has been moved in the opposite direction than that used to provide the normal opening operation of the door as described above, so that the arms 5 and 6 lie one above the other, with a zero angle between them. With this fully aligned arrangement of the arms 5, 6, the door is completely locked, via the arms 5 and 6 and their articulation members, without any need for a further locking mechanism on the frame and/or the door. The strength of the locking provided by this aligned arrangement of the arms depends mainly on the firmness of the door structure. Naturally to use of this form of locking, the guiding track 10 of the guiding member 9 must extend far enough to allow a fully aligned arrangement of the arms to occure.If in turn, instead of the complete locking, it is only desired to stiffen-up the opening movement of the door (as for instance, can be required in a fire door to guard against inadvertent opening under the fire pressure), this can be arranged so that the fulcrum connection provided by the articulation member 11 is not quite shifted to the fully aligned position shown in Figure 6. Then the arms 5 and 6 form a small angle, but the moment exerted on the door by the door closer is, however, considerably greater than for instance, in the positions of the arms shown in Figures 1 to 5. In these Figures, it will be noted that the guiding track 10 is drawn considerably shorter than in Figure 6.

Figures 7a and 7b show one embodiment of apparatus for accomplishing the required displacement of the end of the arm 6. In this arrangement the articulation member 11, located at the end of the arm 6, is supported by means of a nut n-,smber 20 to a slide member 17, which can move within the guiding track 10 of the guiding member 9 and is guided therein by means of the inner walls thereof. To effect the displacement, the guiding member 9 is provided with an actuator 18, which with advantage can be an electric motor and which moves the slide member 17 by means of a screw member 19 and the nut member 20.

Figure 8 shows the basic principles of one form of control system for an apparatus according to the invention. For moving the slide member 17 and for controlling the operation of the actuator 18, the apparatus is provided with a control unit 22, to which is fed a signal (on a line 24) derived from a sensor/ switch 23. The signal on line 24 indicates whether the door is closed or not, and further signals, from position detectors 21 (see Figure 7a), indicating the end positions of the member 11, are fed to the unit 22 via lines 25. As shown in Figure 7a, the position detectors 21 can be microswitches. From a sensing of the control signals on the lines 25 and/or a sensing of impulses received from a rotation sensor (not shown) attached to the shaft 7 of the door closer 4, the control unit 22 acts to energise the actuator 18 by means of a signal fed to it on a line 26.The operation of the actuator 18 is stopped either by means of signals received from the micro-switches 21, or by means of the impulses from the rotation sensor on the shaft 7, when the member 11 reaches an end position on the track 10.

Figure 9 shows one embodiment of a circuit for controlling the operation of the actuator 18 which causes the movement of the fulcrum at the end of the arm 6. The circuit shows the situation indicated in Figure 1. A relay 28 sets contacts 27a and 27b according to the position of the switch 23 indicating the state of openness of the door 2. When the door is closed, the switch 23 is also closed and the relay 28 is energised. With the relay 28 activated, the contacts 27a, 27b are in the lower positions shown in Figure 9. When the door is opened, the switch 23 also opens, deenergising the relay 28 and causing the contacts 27a, 27b of the relay to move into the upper position shown in Figure 9.

When the fulcrum of the arm 6 of the closer 4 is being moved from one end position to the other, both switches 21a and 21b, shown in Figure 9, are closed. Just before the arm 6 reaches either of its end positions, the appropriate one of the switches 21a or 21b, corresponding to the end position in question, opens. Hence, when the fulcrum of the arm 6 of the closer 4 is in either of its end positions, one of the switches 21a and 21b will be open and the other will be closed. Depending on the position of the contacts 27a and 27b and the switches 21a and 21b, the circuits of relays 29a and 29b are either energised or deenergised and, on the basis of this, the position of contacts 30a and 30b is set in a manner similar to that described above. The position of the contacts 30a, 30b, also determines whether the actuator 18 is energised or not.Thus the actuator 18 receives the control required for its starting and stopping. It should be noted, that in Figure 9 the upper position of all the contacts 27a, 27b, 30a and 30b corresponds to the passive state of the respective relay 28, 29a or 29b and the lower position thereof corresponds to the energised state of the respective relays.

Thus, in the situation shown in Figure 9, the door is closed so the switch 23 is closed and the contact 27a is also closed. Since the switch 21a is open, the relay 29a is not energised and the contact 30a is in its upper position as shown in Figure 9. The contacts 27b and 21b are open and closed respectively, so that the relay 29b is passive and does not move the contact 30b, which is in its upper position as shown in Figure 9 Thus, contacts 30a and 30b are both connected to the same pole of the power source so that the actuator 18 is not energised.

When the door is opened, the switch 23 opens and the contacts 27a and 27b are moved into the upper positions shown in Figure 9. The relay 29b is now energised and the contact 30b is moved down to its lower position shown in Figure 9. The actuator 18 is now connected across the poles of the power source and, consequently, starts to move the end of the arm 6 of the door closer within the guiding track 10 of the guiding member 9 (compare Figures 1, 2 and 7). As a result of this, the switch 21a is closed, which, however, does not change the state of the relay 29a and the associated switch 30a.

When the door is fully open, and the end of the arm 6 has been moved to its other end position within the guiding track 10, the switch 21b opens and disconnects the circuit of the relay 29b, whereby the contact 30b moves into its upper position in Figure 9. Since the switch 30a is still in its upper position as well, the actuator 18 is again connected to only one pole of the power source, and becomes deactivated and thus stops.

When the door is in the final stage of a closing movement and is open only about 1 to 3 , the switch 23 closes resulting in the shifting of the contacts 27a and 27b back into their lower position shown in Figure 9. Since the switch 21a is now closed, the relay 29a is energised and the contact 30a is moved to its lower position. On the other hand, since the contact 27b is now open, the relay 29b is not energised, so the contact 30b remains in its upper position causing the actuator 18 to restart.Since the contacts 30a and 30b are now connected to the opposite poles of the power source relative to the situation existing during the opening movement of the door as described above, the actuator 18 now runs in the opposite direction and begins to move the end of the arm 6 of the door closer 4 within the guiding track 10 back towards its initial position, the switch 21 b being closed. In the final phase of the closing movement of the door, the switch 21a opens, de-activating the relay 29a and moving the contact 30a to its upper position. As a result of this, the actuator 18 stops, and the positions of the contacts and the switches again correspond to those shown in Figure 9.

The connection arrangement shown in Figure 9, given by way of example, ensures such a shifting of the arms 5 and 6 of the door closer, that the opening of the door is easier than normal ad the closing of the door is effected more forcefully. To effect the shifting of the arms 5 and 6 shown in Figure 6 so that the door is locked in its closed condition, requires the provision of a separate control system. This can be arranged, for example, by providing the control unit 22 with a programmable microprocessor, which provides for the necessary further movement of the member 11 after the door has closed.This can be carried out, for instance, such that the microprocessor, having received an initiating signal for accomplishing locking of the door from, for example, an operator or some control unit including a timing device, is arranged to turn the switches, contacts and relays in Figure 9 to a pOsition, in which the actuator 18 re-starts and runs in such a direction so as to shift the member 11 of the arm 6 of the door closer in the guiding track 10 of the guiding member 9 to the position required to align the arms 5 and 6. If desired the provision of the control for starting and stopping the actuator by means of the mechanical switches shown in Figure 9 as well as the provision of the locking of the door, in which the said switches are also made use of, as described above, can alternatively be arranged by a microprocessor provided with suitable progamming for accomplishing the operational measures required. The separate programming commands for these measures can be carried out on the basis of signals fed to the lines 24 and 25 (Figure 8) and a signal, indicating a requirement for locking of the door, supplied by an operator or by a control unit duly programmed and provided with a timer.

The invention is not limited to the embodiments shown, since several modifications thereof are feasible with the scope of the following claims.

Claims (14)

1. A method for controlling the force exerted by a door closer on a door, the door being connected by hinge means to a door frame and linked to the door frame by means of first and second arms which form an articulated arm assembly, the ends of which are respectively pivotally connected on one hand at a fulcrum connection to one of the door and its frame and on the other hand to the door closer to link the door closer to the door, which method involves moving the said fulcrum connection relative to the hinge means to change the turning moment exerted on the door by the door closer in a desired way in separate phases of the opening and closing movements of the door within its frame, the shifting of the fulcrum connection being such that the turning moment exerted on the door by the door closer is considerably increased when the door is in its closed position.

2. A method according to claim 1, in which for the initial phase of an opening movement of the door, said fulcrum connection is shifted, relative to the hinge means, so that the turning moment exerted on the door by the door closer is decreased, and, after opening of the door slightly, said turning moment is increased so that it is at its maximum value at least when the door is fully open and reclosing of the door commences.

3. A method according to claim 2, in which the increase of said turning moment during an opening movement of the door and the decrease during a closing movement of the door each occur when the door is open less than 3 from its closed position.

4. A method according to claim 2, in which the increase of said turning moment during an opening movement of the door and the decrease during a closing movement of the door each occur when the door is open between 1 and 3" from its closed position.

5. A method according to any preceding claim, in which the said fulcrum connection is moved relative to the hinge means so that the angle between the articulated first and second arms approaches alignment of the arms for accomplishing a complete locking of the door in the closed position.

6. A method for controlling the force exerted by a door closer on a door substantially as hereinbefore described, with reference to, and as illustrated in the accompanying drawings.

7. Apparatus for controlling the opening/closing of a door, which apparatus comprises a door closer and first and second arms which are articulated with each other to form an articulated arm assembly by means of which a door is linked to a door frame, wherein for controlling the force exerted on the door by the door closer, the apparatus includes means for changing, in a desired way, the position of the fulcrum connection of the remote end, relative to the door closer, of the articulated arm assembly and, hence, the moment exerted on the door by the door closer in separate phases of opening and closing of the door, and, for preventing opening of the door in its closed position, the shifting range of said fulcrum connection includes a location for the fulcrum connection, in which the moment exerted by the door closer on the door is considerably increased.

8. Apparatus as claimed in claim 7, in which a location of the fulcrum connection is possible in which the angle between the arms of the articulated arm assembly is decreased to a minimum value such as to provide for locking of the door in the closed position.

9. Apparatus according to claim 7 or 8, in which the fulcrum connection of the articulated arm assembly is provided on a slide member, which is linearly movably supported in a guiding member mounted on the door, the apparatus further including an actuator for shifting said slide member and means for determining the end positions thereof in the guiding member.

10. Apparatus according to claim 9, in which a control unit is provided, which is arranged to energise the actuator, on the one hand at a pre-set open position of the door and to shift the slide member to a desired position as presupposed by the change of the moment exerted on the door by the door closer, and on the other hand, in the closed position of the door, to shift the slide member, when desired, to a position for effecting 'ock- ing of the door in the closed position.

11. Apparatus according to claim 10, in which sensing means is provided for indicating to said control unit when the door is almost closed.

12. Apparatus according to any of claims 9 to 11, in which the guiding member is provided with micro-switches for determining when the slide member is in its respective end positions and for controlling the operation of the actuator via the control unit.

13. Apparatus for controlling the opening/closing of a door substantially as hereinbefore described.

14. Any novel method or apparatus feature disclosed but not otherwise claimed.