GB2486971A - A floor mounted door actuator unit for swing door - Google Patents

Abstract

A floor mounted door actuator unit 1 for a swing door 24, comprising: a chassis 7 supported by a floor; a drive spindle 9 rotatably mounted on the chassis, the spindle 9 engaging and supporting a door 24 for rotation of the door about the spindleâ s 9 axis of rotation; an electric motor 16a; a controller 16b for the motor; a first pulley 20 coaxially arranged with and engaged with the spindle; a second pulley 17 connected to the motor; at least one drive belt 18, 19 for connecting the motor 16a to the first pulley 20 so that operation of the motor 16a causes the first pulley to rotate the spindle 9; and a torsion spring 21. Operation of the motor 16a drives door 24 connected to spindle 9 from a first position to a second position against the action of the spring 21 and the spring 21 can return the door 24 to the first position if the motor controller 16b should fail. The torsion spring may be a spiral or helical spring wound around a pulley axis. The unit may have a learning mode, learning from temporary physical stop positions and subsequently allowing movement between the learnt positions.

Description

Actuator Unit The present invention relates to a floor mounted door actuator unit for a swing door.

Floor mounted door actuator units typically comprise a casing to be embedded in the floor with a top plate to be mounted flush to the surface of the floor. A drive spindle protrudes through the top plate to which a door is directly mounted, about which the door pivots and on which the weight of the door is supported. The actuator units are normally relatively robust, for they directly support the weight of the door, which may be quite considerable in the case of a relatively large plate glass door of the type commonly used as an entrance door in commercial buildings. In addition to being able to support the weight of the door, the actuator unit also has to be strong enough to keep the door closed in adverse weather conditions and! or to prevent unauthorised access.

One example of a floor mounted door closure unit is manufactured by Geze Ltd. This comprises a housing within which an electric motor, mounted in one end of the housing, drives a hydraulic unit. The hydraulic unit has a number of adjustments for controlling the position of the door. The hydraulic unit has an output drive shaft that extends through both sides of a casing of the hydraulic unit. The shaft engages with an input shaft of a gear box, which input shaft similarly extends to both sides of the casing of the gearbox. In this way the gearbox may be mounted in the door closure unit housing to either side of the hydraulic unit, depending on whether door closure unit is a left-hand or right-hand unit. The gearbox has a vertical output shaft, which is the spindle upon which the door is mounted and which carries the weight of the door.

Door closure units of the above type perform very well but are relatively expensive to manufacture, comprising a separate hydrostatic unit and gearbox including a relatively large number of machined parts. The footprints of such units are also relatively wide due to the gearbox being mounted to one side of the hydrostatic unit.

According to a first aspect of the present invention there is provided a floor mounted door actuator unit for a swing door, the unit comprising: a chassis arranged to be supported by the floor; a drive spindle rotatably mounted on the chassis and supported by the chassis, the drive spindle being arranged to engage with and support a door for rotation of the door about the axis of rotation of the spindle; an electric motor; a controller for the electric motor; a first pulley coaxially arranged with the spindle and engaged with the spindle; a second pulley connected to the motor; at least one drive belt for connecting the motor to the first pulley so that operation of the motor causes the first pulley to rotate with the spindle; and a torsion spring, wherein the torsion spring and electric motor are arranged such that operation of the motor will drive a door connected to the spindle from a first position to a second position against the action of the spring and the spring can return the door to the first position.

Employing the present invention avoids the need to have a gearbox supporting the weight of the door. Instead the door is supported by the spindle which in turn is supported by the chassis. Rotation of the spindle, and thus the position of the door, is then controlled by the pulley and drive belt arrangement. The number of components can thus be significantly less than in an arrangement employing a gearbox and some of the components, such as the pulleys, may be injection moulded, reducing the number of machined parts that may otherwise be required.

In the context of the present claims the term "pulley" is to be interpreted to include both pulleys and toothed cogs.

In addition to the above, the provision of the torsion spring permits the door to be automatically closed if power supply should fail, which may happen in the event of a fire, or which may be triggered in the event of a fire alarm.

Preferably, the torsion spring is a spiral or helical spring wound around the axis of a pulley within the unit. This permits the automatic closure of the door, on failure of the power supply, to be achieved by the unit while adding relatively little additional expense to the cost of manufacture of the unit. Furthermore, the provision of the torsion spring around the axis of a pulley provides a very compact return mechanism within the unit and may be arranged so that the dimensions of the unit are no greater than they would be had the spring not been present.

Preferably, the unit further comprises third and fourth pulleys of different diameters S arranged coaxially and engaged with each other, the unit comprising a first belt connecting the second and third pulleys and a second belt connecting the third and first pulleys, such that said arrangement of pulleys reduces the drive ratio between the motor and the spindle, the motor, pulleys and spindle being linearly arranged with the motor at a first end of the unit and the spindle and first pulley at the second end of the unit opposite the first end.

The above arrangement reduces the output drive of the gearbox by using a plurality of pulleys and drive belts, but permits these to be arranged in a linear arrangement such that the overall width of the casing can be kept to a minimum with the spindle located towards one end of the housing.

Such a unit may be mounted perpendicular to the door when the door is in the closed position such that it lies along the skirting of a passageway leading to the door. The relatively narrow width of the unit means the unit does not protrude into the walkway area.

Alternatively, the unit may be aligned with the door when the door is in the closed position, thus extending across the walkway. In this configuration, the relatively narrow width of the unit means that a significant part of the top plate of the unit is concealed by the width of the door, when the door is in the closed position.

It is advantageous, where the housing is elongate, if the spindle is no more than 65mm from an end of the housing. This permits the housing to be mounted across a doorway with the spindle mounted 65mm from the doorframe, (which is an industry standard), without the unit extending below the doorframe, or into the doorframe where the doorframe extends below the level of the floor.

It is also advantageous that the spindle is no more than 65mm from either side of the housing, enabling the housing to be mounted perpendicular to the doorway, possibly along the skirting of the passageway leading to the doorway. It is advantageous if the housing is rectangular and its length is at least 2.5 times greater than its width. It is also advantageous if the housing is less than 130mm wide.

S Advantageously, the spindle is mounted on the chassis by a conical bearing which enables all the weight of the door on the spindle to be supported by the rollers of the bearing.

Preferably, the unit can be modified to operate as a right hand closing or right hand opening unit by reprogramming the motor controller and by reversing or replacing the spring.

Advantageously the, or each, belt is a toothed belt and the, or each, pulley is a toothed cog, which avoids possible slippage and wear of the belts.

Preferably, the unit comprises an elongate housing having a base plate to be secured in the floor, wherein the base plate and chassis are ananged such that the chassis can be fixed to the base plate in different positions in the longitudinal direction of the housing.

This enables the housing to first be mounted in the floor and then the exact position of the spindle to be subsequently adjusted.

Preferably, the spindle can be rotated by the motor through more than 180° and more preferably by more than 270°. This is possible by a pulley being mounted on the spindle such that the drive belt may infinitely rotate the spindle in either direction. Such an anangement may be advantageous where a door attached to the unit is located in a doorway in a wall, where it is desired to open the door fully back against the wall, or to permit the door to be opened in both directions. This will also apply to a door mounted in a corridor location.

It may also be desirable, in an application such as on the inner end of an entranceway, to be able to rotate the door from a closed position across the entranceway, through nearly 270° so that it lies substantially flat against the back of the wall of the entranceway.

It is particularly advantageous if the controller may be set to a learning mode, so that when a door is mounted on the spindle, the motor operates the door in one direction until it reaches a temporary physical stop and then operates the door in the opposite direction until the door reaches a second temporary physical stop, with the controller subsequently controlling the movement of the door between these two positions. This permits the unit to be simply installed in a desired location, a door connected to the unit and then the unit operated with physical stops corresponding to a desired closed position and desired open position so that the unit may learn the desired closed and open positions. The controller may then subsequently control operation of the door between these two positions once the temporary physical stops have been removed.

According to a second aspect of the present invention there is provided a doorway comprising a unit as described above and a swing door mounted to the unit by the spindle, wherein the unit is arranged to open the door from a closed position to an open position and retain the door in the open position and wherein the spring is arranged to return the door to a closed position if the electrical supply to the motor controller should fail.

This arrangement provides an electrically operated door which will close the doorway if the electrical supply to the motor controller should fail. This may thus be used to automatically close the door in the event of a fire or a fire alarm. However, it is preferable that the door may still be opened manually in the event of failure to the power supply, permitting evacuation of the building, which is facilitated by it being possible to open the door against the spring pressure.

In an alternative embodiment, the doorway may further comprise an electrically operated retainer arranged to retain the door in a closed position, but wherein when the electrical supply to the unit fails and the electrically operated retainer is released, the door under the action of the spring may pass through the closed position to a second open position in the opposite direction to the normal open position.

This alternative arrangement permits the door to operate normally between a closed position, where it is retained in place by an electrically operated retainer such as an electromagnet which is released immediately prior to operation of the motor, but permits the door to open under the action of the spring when the retainer is released In the case where the retainer is an electromagnet, this will occur automatically on failure of the power supply to the magnet, permitting the door to open to the second position in the opposite direction to the normal open position. This may have application where in normal use the door opens into a building, but in the event of a fire or emergency the electrical supply to the door may be cut, resulting in the door opening outwards.

In a further alternative aspect of the invention, there is provided a doorway comprising a unit as described above, a swing door mounted to the unit by the spindle and an electrically operated retainer alTanged to retain the door in a closed position, wherein the retainer is ananged to be released to permit the door to be moved to a first open position, from where it returns under the action of the spring to the closed position to be retained in place by the retainer, wherein the retainer may be released and the motor activated to drive the door to a second open position in the opposite direction to the first open position. The motor controller l6b may be set to allow the door to be opened to the first position either manually or by the motor 16a.

The above arrangement of doorway permits the door to be opened and closed by the unit 1, or manually, in normal operation, the door for example normally being opened into the building, but provides a way of driving the door to a second open position opposite to the normal first open position, in which second position the door may for example be opened out of a building. This may be desirable either in an emergency situation or when it is expected that a large volume of traffic is expected through the doorway in one direction, for example at the end of an event in a stadium or theatre.

One embodiment of the present invention will now be described, by way of example only, with reference to the accompanying drawings, of which: Figure 1 is a perspective view of a door closure unit in accordance with the present invention with the cover plate removed; Figure 2 is a plan view of the unit of Figure I with the cover plate removed; Figure 3 is a cross section along the line Ill-Ill of Figure 2; Figure 4a is a plan view of a doorway employing a door closure unit of figures 1 to 3 in a closed position; Figure 4b is a plan view of the doorway of Figure 4a in a first open position; Figure 4c is a plan view of the doorway of Figures 4a and 4b in a second open position; Figure 5a is a plan view of a further doorway implying a door closure unit of Figures 1 to 3 in a closed position; Figure Sb is a plan view of the doorway of Figure 4a in normal open position; and Figure Sc is a plan view of the doorway of Figures 4a and 4b in a second open position.

Referring to Figures 1 to 3, a door closure unit 1 indicated generally as 1 comprising a housing 2 and a cover plate 3. The housing 2 is arranged to be secured in the floor by means of fastenings 4, seen in Figures 2 and 3, or to be fitted to a purpose built cradle (not shown), which is itself fitted to the floor. Alternatively, or in addition to fastenings 4, the housing 2, or a cradle, may be concreted into the floor.

Located in the bottom of the housing 2 is a base plate 5 having a number of slotted apertures 6 therein through which the base plate 5 is bolted to the housing 2. The slotted apertures 6 enable base plate 5 to be moved longitudinally forwards or backwards relative to the housing 2.

Welded to the base plate 5 is a relatively thick steel chassis plate 7 towards one end of which is mounted a conical bearing 8. The conical bearing 8 supports a spindle 9. The spindle 9 comprises a main spindle shaft 9a and an adaptor 9b. The adaptor 9b may be selected from a range of adaptors depending on the fitting present in a door (not shown) to be mounted on the spindle 9 and the clearance desired between the door and the floor.

Alternatively, the main spindle shaft 9a could extend through the cover plate 3 and engage directly with the door.

Also bolted to the chassis plate 7 is a C-shaped steel member 10 having a top plate lOa and a bottom plate lOb. The top plate lOa carries bearing 11 maintaining the top of the spindle 9 in position and bottom plate lOb carries a similar bearing which gives additional axial support to the lower section of the spindle 9a. The top plate lOa also carries bearing 12 vertically aligned with a bearing 13 mounted in the bottom plate lOb of C-shaped member 10. Bearings 12 and 13 carry shaft 14 on which teethed cogs iSa and 15b are secured for rotation therewith. The cogs iSa and 15b may be formed separately or as one piece. Also attached to the chassis plate 7 is a motor 16a which, via toothed cog 17 (see Figure 1) drives first toothed belt 18 which via cogs ISa and 15b drives second toothed belt 19. The second toothed belt 19 drives toothed cog 20 fixed to spindle 9. Although toothed cogs are illustrated and preferred, as they are less prone to slipping than v-belts or other toothless belts, toothless belts and pulleys could be used instead of the toothed belts and cogs illustrated.

Below the toothed cog 20 is mounted a helical torsion spring 21 upon spring carrier 22. A first end of the spring 21 engages in aperture 23 of bottom plate lOb. The other end of the spring 21 engages with the cog 20 and the spring 21 is pre-biased such that it returns the cog 20 to its starting position, which may correspond to the door being in the closed position when mounted on the spindle 9 or a position past the normally closed position.

In use, the unit I is mounted in the floor with spindle in the correct position to align with the corresponding engagement point of a door, normally 65mm in from the doorframe.

The unit 1 is mounted such that the top surface of the cover plate is flush with the surface of the floor.

In use, standard control electronics, not illustrated, detects that the door is to be opened, either by a switch being depressed, or an electronic sensor detecting movements in the vicinity of the door, whereupon the motor controller i6b actuates the motor 16a. The motor 16a, typically a 24 volt DC motor, drives the spindle 9 via drive belts 18 and 19 and associated cogs iSa, 15b, against the spring 21 opening a door connected to the spindle 9.

When the door reaches its fully opened position, the control circuitry detects this and stops the motor lGa with the back EMF of the motor preventing the spring 21 returning the door to its closed position.

When it is desired to close the door, or in the event of power failure, the motor 1 6a is normally switched so that no back EMF is present and the spring 21 drives the motor 16a in the opposite direction until the door is closed. Alternatively, the motor controller 1 6b can drive the motor 1 6a in the opposite direction at a predetermined rate until it is detected that the door has reached its closed position.

The motor controller 16b will normally receive its electrical energy from an external control unit (not shown), typically wall mounted, which will in turn receive control signals from external switches. These may be one or more push buttons, or similar, located adjacent a door attached to the unit, or PIR or similar motion sensors for detecting movement to one or both sides of a door mounted to the unit 1, all of which is commonly employed with automatic doors. Such an external control unit will then transmit appropriate signals to the motor control unit 16b.

The external control unit may also receive inputs from an authorised person, setting a mode of operation for the unit 1 and a door attached thereto. For example the unit I may be set to a closed "locked" position to resist opening of the door by the motor controller l6b connecting the motor 16a so that a back electromagnetic field (EMF) is generated in response to the motor 16a trying to rotate. The back EMF opposes rotation of the motor 1 6a and thus opposes opening of the door. Alternatively the motor controller 16b may be set so that no back EMF is generated, permitting the door to be pushed open, in this case against the torsion spring 21. Also the door may be set to a permanently open position.

However, the motor can be controlled in a number of different ways, some of which are described below with reference to Figures 4a to Sc.

The unit 1 has a maximum width of 130mm with the spindle centrally located such that it is not only 65mm from the end but also 65mm from either side of the housing 2 of the unit 1. This enables the unit I to either be mounted across the threshold of the doorway or along the edge of a skirting leading along the passage leading to the doorway.

The unit 1 may either function as a right hand closing or right hand opening unit 1 by selection of appropriate drive circuitry for the motor and by fitting either a spring 21 wound clockwise or a spring 21 wound anti-clockwise.

Referring now Figure 4a, a door 24 shown mounted to unit 1 via an offset strap 25 mounted at the bottom of the door. A similar offset strap (not shown) be provided at the top of the door connecting to a pivot point axially aligned with the spindle 9 of the unit 1.

The door 24 is shown located in an entranceway defined by walls 26 to 27 with A representing the inside of the building and B representing the outside.

The door in normal operation will operate between the closed position, shown in Figure 4a, and the open position, shown in Figure 4b where the door has rotated through 900, as represented by the arrow 28.

When the unit 1 has been installed in the floor and a door 24 fitted thereto, an authorised person may access an external control unit 30 for the motor controller 16b and set the motor controller to a learn mode. In this mode, the unit 1 opens the door until it reaches a temporary physical stop in the position illustrated in Figure 4b. The unit then reverses the motion of the door until it attains the position shown in Figure 4a where the door 24 encounters either a temporary or permanent physical stop. The external motor control unit 30 can then be set to an operational mode where, in response to the presence of an individual which requires to pass through the door, detected either via pushbutton controls, under floor pressure detectors, PW detectors or the like, the door opens to the position shown in Figure 4b before returning to the closed position shown in Figure 4a, in a conventional manner. Alternatively, an authorised individual may access the external control unit and set motor controller 16b to lock the door in one of the positions shown in Figures 4a or 4b or alternatively to a position illustrated in Figure 4c which has previously also been learnt' by the motor controller 16b.

The anangement of the components of the unit 1, as previously described with reference to Figures 1 to 3 may permit the door to be opened to any desired position, there being no mechanical constraint in the unit 1 which restricts rotation of a door 24 mounted to the spindle 9.

Referring now to Figures 5a to Sc, a door 24 mounted to unit 1 via spindle 9 is shown as forming a doorway between walls 31, 32, which define a corridor with side A extending towards to the inside of the building and side B extending towards an exit. The unit 1 is shown located lying along the wall 32, so that the cover plate 3 does not extend into the walkway area.

Although the doorway formed by door 24 is shown in Figures Sa to Sc as being located in a corridor, it could equally be located at the end of a corridor in a flat wall and the following description would apply equally to the doorway mounted in such an alternative location.

Referring to Figure 5a, the door is retained in a closed position by an electromagnet 33 acting on steel plate 34 on the edge of door 24. Electromagnet 33 is shown illustrated as forming part of the upright of the door frame, but the electromagnet 33 could be mounted above or below the door with the steel plate on the top or bottom edge of the door. When the electromagnet 33 is activated and the door passes the position shown in Figure Sa, the door 24 is effectively locked in that position by the strength of the electromagnet 33.

In one arrangement the door may operate between the positions shown in Figure Sa and Figure Sb in the same manner as previously described with reference to Figure 4a and Figure 4b, with motor controller 16b controlling the position of the door and retaining the door in the closed position 24, with the electromagnet 33 acting as an additional security lock.

In an alternative arrangement, the motor controller may be set to allow the door to be manually opened to the position shown in Figure Sb by a pedestrian pushing or pulling the door open. The door then returns under the action of the torsion spring 21 to the closed position illustrated in Figure 5a where it is retained in place by electromagnet 33. To open the door, the electromagnet 33 first has to be deactivated either by the pedestrian operating a switch or PIR detector. In this arrangement, in the event of a fire the unit 1 may be activated to drive the door to a second open position illustrated in Figure Sc and to retain the door in this position opening towards or forming an exit from the building.

In yet a further embodiment, the door may be operated by the unit 1 between a closed position illustrated in Figure 5a and the normal open position illustrated in Figure Sb whereby the motor controller is set such that in the event of the failure of power supply to the unit 1 and to the electromagnet 33 the door will open to a second open position illustrated in Figure Sc under the action of the torsion spring 21.

Several embodiments of the present invention have been described by way of example only and a skilled person will realise that many modifications are possible to this design which modifications fall within the scope of the appended claims.