EP1306507A1

EP1306507A1 - A method of making arrangements for controlling the closing movement of a sliding door

Info

Publication number: EP1306507A1
Application number: EP01610109A
Authority: EP
Inventors: Michael Erik Lemming
Original assignee: N Norholm & K Lemming AS
Current assignee: N Norholm & K Lemming AS
Priority date: 2001-10-24
Filing date: 2001-10-24
Publication date: 2003-05-02
Also published as: NO20025096L; NO20025096D0

Abstract

A speed control device (10) for controlling the closing movement of a sliding door (28) may be used in at least two of the following and in several other manners, whereby production costs and storage expenses may be substantially reduced:

(a) connecting or engaging one end part of a wire of a wire and pulley drive to the door (28), passing the wire (33) around a guide pulley arranged at the side of the door opening opposite to the door in its open position, stationarily fastening an other end part of the wire, and suspending the speed control device (10) in a wire loop formed between the guide pulley and said other end of the wire, whereby the control device forms at least part of a biasing weight (35),

(b) fastening the frame of the speed control device (10) stationarily at one side of the door opening opposite to the door in its open position and connecting or engaging one end part of the wire (33) to the door (28) and another end part to a weight (35) for biasing the door towards its closed position, when a releasable retaining device (23, 24) is released,

(c) fastening the frame to the upper part of the door (28), which is slidable along a supporting rail (29) being inclined so as to bias the door towards its closed position by its own weight, and connecting opposite end parts of the wire (33) to stationary building parts, such that the wire extends along said rail.

Description

The present invention relates to a method of making arrangements for controlling the closing movement of a sliding door of the type, which is movable between open and closed positions and biased from its open towards its closed position, when a releasable retaining device is released.

Different types of such sliding doors are known. Thus, they may be biased towards their closed position by a vertically movable weight, or they may be slidably mounted on a slightly inclined rail so that the door is biased towards its closed position under the influence of its own weight. Furthermore, some sliding doors are moving to the right and other doors to the left when closing. Additionally, some doors are constantly held in their open position by the releasable retaining device and can not be closed until the retaining device is released, while other doors may be freely opened and closed, but are forced to their closed position when the retaining device is released, for example in case of fire.

Various kinds of controlling arrangements of the above type are known. Thus, in some of the known arrangements the speed control device or braking device is mounted stationarily in relation to the doorframe or to the door, and in other arrangements it is mounted on a weight used for biasing the door towards its closed position. Examples of such known arrangements and releasable retaining devices are disclosed in EP-A-0 081 189, DE-C-668 313, FR-A-972 425, EP-B-0531 246, DE-U-299 09 694, and EP-A-0 530 425.

In order to satisfy all requests from customers, manufacturers and distributors of such controlling arrangements for sliding doors must produce and stock a large number of different items, whereby costs are substantially increased.

The object of the present invention is to reduce such costs incurred by the need for producing and stocking spare parts for a large variety of different arrangements.

The present invention provides a method of making arrangements for controlling the closing movement of a sliding door, which is movable between open and closed positions and biased from its open towards its closed position, when a releasable retaining device is released, said arrangement including a speed control device having a frame, braking means with a rotor rotatably mounted on the frame, a wire and pulley drive drivingly connected to the door and to the rotor such that the rotor is rotated when the door is moved into its closed position due to release of the retaining device, said method comprising the use of such speed control device in at least two of the following manners:

(a) connecting or engaging one end part of the wire to the door, passing the wire around a guide pulley arranged at the side of the door opening opposite to the door in its open position, stationarily fastening an other end part of the wire, and suspending the speed control device in a wire loop formed between the guide pulley and said other end of the wire, whereby the control device forms at least part of a biasing weight,

(b) fastening the frame of the speed control device stationarily at one side of the door opening opposite to the door in its open position and connecting or engaging one end part of the wire to the door and another end part to a weight for biasing the door towards its closed position, when the releasable retaining device is released,

(c) fastening the frame to the upper part of the door, which is slidable along a supporting rail being inclined so as to bias the door towards its closed position by its own weight, and connecting opposite end parts of the wire to stationary building parts, such that the wire extends along said rail.

Thus, according to the present invention the same speed control device may be used for at least two and preferably three different types of arrangements for controlling the closing movement of a sliding door, whereby production and stock costs may be reduced substantially.

According to the invention the frame of the speed control device may be fastened stationarily at one side of the door opening opposite to the door in its open position and a dog or carrier is connected to the wire, the dog or carrier being adapted to engage with the door and move it towards its closed position when the retaining means are released, and connecting another part of the wire to a weight for biasing the dog or carrier into engagement with the door for moving the same.

The method according to the invention may comprise fastening to the wire a dog or carrier adapted to engage with the door and move it towards its closed position when the retaining means are released, the wire being passed around a guide pulley arranged at the side of the door opening opposite to the door in its open position, and stationarily fastening an end part of the wire, and suspending the speed control device in a wire loop formed between the guide pulley and said stationarily fastened end part of the wire, whereby the control device forms at least part of a biasing weight for biasing the dog or carrier and, consequently, the door towards its closed position when the retaining means are released.

The frame of the speed control device preferably comprises a substantially closed housing containing the rotor of the braking means and first and second mutually spaced pulleys of the wire and pulley drive. In such case the housing may comprise first and second housing parts carrying the first and second pulleys, respectively, said first and second housing parts being mutually hinge connected. Thereby service and repair is substantially facilitated. In the preferred embodiment the axis of the hinge connection extends substantially parallel with the rotational axis of said first pulley.

The housing of the speed control device may have any practical shape. In the preferred embodiment, however the housing is substantially parallelepiped shaped.

The braking means may be of any suitable type, such as a frictional brake. Preferably, however, the braking means comprise an eddy current brake having a rotor, which is driven by the first pulley via meshing gearwheels, one of said gearwheels being mounted on its shaft by means of an overrunning clutch or similar means transmitting the rotational movement of the first pulley to the brake rotor in one rotational direction only.

In case the speed control device forms part of a biasing weight, the pulleys of the wire pulley drive may comprise a wire reversing pulley rotatably mounted on the frame and having a peripheral, circular groove or track formed therein for receiving said wire and defining a first plane, a guide pulley being rotatably mounted on the frame above the reversing pulley and defining a circular groove or track therein defining a second plane, which defines an acute angle with said first plane, whereby the wire may be passed around the reversing pulley and into engagement with opposite sections of the guide pulley such that the wire parts extending between the pulleys are mutually crossing without contacting each other.

The sliding door is preferably held in its open position by electromagnetic forces, and the biasing means, such as a spring or a weight, may then become activated, when an electric current generating the electromagnetic forces is interrupted. The retaining means may comprise an electromagnet, which is mounted on the doorframe and is in engagement with a ferromagnetic member fastened to the door. In the preferred embodiment, however, the electromagnetic forces are blocking the rotational movement of the rotor of the braking means or other rotatable elements drivingly connected therewith. Thus, the rotor of the braking means may be held stationary by an electromagnet. In order to obtain an increased holding torque the electromagnet is preferably positioned spaced from the centre axis of the rotor.

In case the sliding door may be moved freely between its open and closed positions because of the arrangements described in (c) or (e) above, the part of the wire and pulley drive on which the carrier or dog is mounted, is preferably formed into a closed loop, which is passed around a guide pulley at one side of the door opening opposite to the frame of the speed control device.

The present invention further provides an arrangement for controlling the closing movement of a sliding door, which is movable between open and closed positions, said arrangement comprising biasing means for biasing the door towards its closed position, releasable retaining means for retaining the biasing means in an inactive condition or position, a speed control device having a frame, braking means with a rotor rotatably mounted on the frame, a wire and pulley drive drivingly connected to the door and to the rotor so that the rotor is rotated when the door is moved from its open to its closed position, the retaining means comprising an electromagnetic device, which is positioned adjacent to the rotor of the braking means and adapted to block the rotational movement of the rotor and other rotatable elements drivingly connected therewith, when energised. Thus, under normal conditions the biasing means - which may, for example, comprise a weight, an inclined rail along which the door is movable, or a spring - are retained in their inactive condition, because the rotor of the braking means is blocked. If, however, for some reason, such as in case of fire, the door must be closed the current supply to the electromagnetic device is switched off, whereby the biasing means are activated so as to move the door to its closed position controlled by the speed control device.

In order to increase its retaining torque the electromagnetic device is preferably spaced from the central axis of the rotor.

The invention will now be further described with reference to the drawings, which show a number of different ways in which basically the same speed control device may be arranged in accordance with the present invention. In the drawings

Figs. 1 is a sectional view along the line I-I in Fig. 2 illustrating an embodiment of a speed control device of the type which may be used in connection with a method and an arrangement according to the invention,

Fig. 2 is a sectional view at right angles to that of Fig. 1,

Fig. 3 is a perspective view of the speed control device shown in Figs. 1 and 2 in a first modified embodiment,

Fig. 4 is a sectional view along the line IV-IV in Fig. 5 showing a second modified embodiment of the speed control device shown in Figs. 1 and 2,

Fig. 5 is a sectional view at right angles to that of Fig. 4,

Fig. 6 is a cross-sectional view along the line IV-IV in Fig. 4,

Fig. 7 is a sectional view along the line VII-VII in Fig. 8 of a third modified embodiment of the speed control device shown in Figs.1 and 2,

Fig. 8 is a sectional view at right angles to that of Fig. 7,

Fig. 9 is a top plan view of the speed control device shown in Figs.1 and 2,

Figs 10 is a sectional view of a fourth modified embodiment of the speed control device shown in Figs. 1 and 2,

Fig. 11 is a sectional view along the line XI-XI in Fig. 10,

Fig. 12 is a cross-sectional view along the line XII-XII in Fig. 11,

Fig 13 is a bottom plan view of the control device shown in Figs. 10-12,

Fig. 14 is a perspective view of the speed control device shown in Figs. 1 and 2,

Figs. 15 and 16 each illustrates a sliding door provided with different embodiments of the arrangement according to the invention, in which the speed control device shown in Figs. 1, 2, and 14 is used and mounted on the door frame,

Fig. 17 is a perspective view of the speed control device shown in Figs. 1 and 2 arranged in a different position,

Fig. 18 illustrates a sliding door with a further embodiment of the arrangement according to the invention, in which the speed control device shown in Fig. 17 is used and mounted on the door frame in a different position,

Fig. 19 is a perspective view of the speed control device shown in Figs. 7-9,

Fig. 20 illustrates a sliding door with another embodiment of the arrangement according to the invention, in which the speed control device shown in Figs. 7-9 and 19 is used and mounted on the sliding door,

Fig. 21 is a perspective view of the speed control device shown in Figs. 10-13,

Fig. 22 illustrates a sliding door with a still further embodiment of the arrangement according to the invention, in which the speed control device shown in Figs. 10-13 and 21 is used and mounted on the sliding door,

Fig. 23 is a perspective view of the speed control device shown in Figs. 1 and 2 mounted on a vertically movable biasing weight,

Fig. 24 illustrates a sliding door equipped with another embodiment of the arrangement according to the invention, in which the speed control device shown in Figs. 1, 2 and 23 is used and mounted on the vertically movable biasing weight,

Fig. 25 is a fractional view illustrating a modification of the arrangement shown in Fig. 24,

Figs. 26 and 27 are a perspective view and a side view, respectively, of a wire and pulley arrangement including the speed control device shown in Figs. 10-13,

Fig. 28 illustrates a sliding door provided with the wire and pulley arrangement shown in Figs. 26 and 27,

Fig. 29 is a perspective view of a wire and pulley arrangement including the speed control device shown in Fig. 3, and

Fig. 30 is a perspective view of a wire and pulley arrangement corresponding to those illustrated in Figs. 19-22, but including the speed control device shown in Fig. 3.

Figs. 1 and 2 illustrate a speed control device 10 of the type used for controlling the closing speed of a sliding door, when - such as in the case of fire - the door is biased towards its closed position by some kind of closing forces. The device 10 comprises a frame in the form of a substantially parallelepiped shaped housing. The housing is divided into a basic unit 11 including a rear wall, a pair of opposite sidewalls, and part of a first end wall. The housing further comprises a cover unit 12, which includes a second end wall, a front wall, and part of said first end wall. The cover unit 12 is connected to the basic unit 11 at an edge of the rear wall by means of a hinge connection 13 and may be moved between open and closed positions in a manner illustrated in Fig. 3. In the closed position the

units

11 and 12 may be releasably interconnected, for example by means of screws or bolts 14.

The speed control device 10 comprises an eddy current braking device 15 of known type having a stator and a rotor fixed on a shaft 16, which extends between and is rotatably mounted in opposite housing sidewalls. The efficiency of the braking device 15 may be adjusted in a manner known per se.

A reversing pulley or roller 17 having a peripheral, inwardly tapered groove or track formed therein is fixed on a shaft 18 extending substantially parallel with the shaft 16. The opposite ends of the shaft 18 is also rotatably mounted in the opposite housing side walls. A gearwheel 19 is mounted on the shaft 18 by means of an overrunning clutch or a similar device connecting the gearwheel 19 to the shaft 18 only when the shaft is rotated in one predetermined direction. The gearwheel 19 is engaging with a gearwheel 20, which is fixed on the shaft 16. The diameter of the gearwheel 19 is substantially larger than that of the gearwheel 20 such that rotation of the reversing pulley 17 in a predetermined direction causes the rotor of the braking device 15 to rotate at a substantially higher rotational speed, while rotation of the pulley 17 in the opposite direction does not cause rotation of the rotor because the overrunning clutch does not transfer the rotational movement of the shaft 16 to the gearwheel 19. This means that a sliding door controlled by the device 10 may be moved to an open position without any braking effect performed by the braking device 15.

A guide pulley 21 having a peripheral groove or track formed therein is rotatably mounted on the inner surface of an end wall of the housing opposite to a wall opening by means of a bracket 22. The axis of rotation of the guide pulley defines an acute angle with a plane defined by the axes of the

shafts

16 and 18. When a wire, a string, a line, a rope, or the like is passed around the reversing pulley 17 and into contact with opposite sides of the smaller guide pulley 21, the wire is engaging with the tapered groove therein along a major part of the peripheral length of the groove. Thereby a firm non-slip engagement may be obtained between the wire and the pulley 21. Because the axes of the

pulleys

16 and 18 extend in different, non-parallel directions interference between the crossing wire parts may be avoided.

This basic structure of the speed control device 10 may, for example, be of the type disclosed in the European patent application No. 00610089.5. This basic structure of the speed control device may be modified in a plurality of ways, such as those described below with reference to the drawings, and may then be used in a large number of different arrangements according to the invention for controlling the closing movement of a sliding door, such as those - but not limited to - described below.

Fig. 3 is a perspective view of a modified version of the speed control device shown in Figs. 1 and 2. Thus, the embodiment shown in Fig. 3 comprises an electromagnet 23 mounted on the outer surface of a side wall of the housing of the speed control device 10 opposite to the rotor of the eddy current brake 15. When the electromagnet 23 is energised the rotor of the brake is held stationary, and when the supply of electric power to the electromagnet is interrupted, for example in case of fire, the rotor of the brake 15 is released.

In the embodiment of the speed control device 10 shown in Figs. 4-6 the external electromagnet 23 shown in Fig. 3 has been replaced by an electromagnet 24 mounted on the inner side of the housing by means of a bracket 25. The pole surface of the electromagnet 24 is positioned closely adjacent to the rotor of the eddy current brake 15 and radially spaced from the axis of the rotor. Because of such radial spacing the rotor can be held stationary by means of an electromagnet, which is less powerful than the centrally arranged, external electromagnet 23 in Fig. 3.

Figs. 7-9 show an embodiment, in which the reversing pulley 17 and the guide pulley 21 are arranged outside the housing of the device 10. The reversing pulley 17 is arranged on an external end portion of the shaft 18 adjacent to the gearwheel 19 within the housing, and a thrust bearing 26 is arranged between the pulley 17 and the adjacent outer housing wall. Also the guide pulley 21 is mounted outside the housing of the control device 10 by means of an angle bracket 27 arranged on an end wall of the housing of the control device 10.

The embodiment shown in Figs. 10-13 deviates from that shown in Figs. 7-9 mainly by comprising an electromagnet 24 like that shown in connection with Figs. 4-6 and described above. This means that the rotor of the eddy current brake 15 is locked when the electromagnet 24 is energised and released when the power supply to the electromagnet 24 is interrupted.

It is emphasised that all of the various embodiments illustrated in Figs. 3-13 are based on the basic embodiment shown in Figs. 1 and 2. This means that the various embodiments all comprise the same main elements, and therefore they may be made by making relatively small and cheap changes of the basic embodiment.

Fig. 15 shows a sliding door 28, which is movable along a guide rail 29 on which the door is suspended by means of suspension members 30 with rollers. The door 28 is normally retained in an open position, in which an anchor plate 31 connected to the door is kept in contact with a fixed electromagnet 32. A speed control device 10 as the one shown in Figs. 1, 2 and 14 is stationarily mounted on the door frame. One end of a wire 33 is connected to the door 28 and the opposite end portion is passed through an opening 34 (Fig. 1) into the housing of the control device 10, around the

pulleys

17 and 21 and out through a downwardly directed opening, and the free end of the wire 33 is connected to a biasing weight 35, which may move freely vertically.

Normally, the electromagnet 32 is energised so that it attracts the anchor plate 31 and maintains the door 28 in its open position as shown in Fig. 15. In case of fire a safety fuse (not shown) may cut off the energy supply to the electromagnet. The door 28 will then start moving from its open to its closed position under the influence of the weight 35, and the maximum door closing speed is controlled by the control device 10.

The door arrangement shown in Fig. 15 may be used only in connection with fire doors because the door 28 is normally kept open and closed only in case of fire. Fig. 16 illustrates an embodiment allowing the door 28 to be opened and closed freely. In Fig. 16 the wire 33 is passed through an opening defined in a carrier member 36, which is fastened to the upper surface of the sliding door 28. The anchor plate 31, which in this embodiment is fastened to the free end of the wire 33, is normally retained in engagement with the electromagnet 32. This means that the door 28 may be moved freely between its open and closed positions. In case the supply of electric power to the electromagnet 32 is cut off (for example in case of fire) the anchor plate 31 is released and engaged with the carrier member 36 under the bias of the weight 35, so that the door 28 is moved to its closed position.

The door arrangement illustrated in Fig. 18 is the same as the arrangement shown in Fig. 16 apart from the fact that the door 28 in Fig. 18 is closed in a direction opposite to the door closing direction in Fig. 16. Nevertheless, the same control device 10 may be used in the two arrangements. However, while in the arrangement of Fig. 15 the device 10 is extending vertically as shown in Fig. 14, it is arranged so as to extend horizontally as shown in Fig. 17 when used in the arrangement of fig. 18.

Fig 20 shows a sliding door 28, which is suspended on the guide rail 29 by means of the suspension members 30. The Guide rail 29 is slightly inclined in relation to horizontal such that the door 28 is biased towards its closed position under the influence of its own weight. The anchor plate 31 is connected to the door 28 and is in abutting engagement with the adjacent pole surface of the electromagnet 32 when the same is energised, whereby under normal conditions the door is held in its open position. When for some reason the power supply to the magnet is cut off the anchor plate 31 is released and the door is moved towards its closed position under the influence of its own weight. In order to avoid that the closing speed becomes excessively high the speed control device 10 in the embodiment shown in Figs. 7-9 and 19 is mounted on the upper surface of the door 28 as shown in Fig. 20. The wire 33 is passed around the

outer pulleys

17 and 21 as best shown in Fig. 19, and the opposite ends of the wire 33 is connected to opposite sides of the door frame and extends along and above the upper edge of the door 28 and the door opening. In this manner the speed of the door movement is controlled by the device 10 as previously explained.

Fig 22 illustrates a door arrangement corresponding to the arrangement shown in Fig. 20. The only difference is that in Fig. 22 the device 10 is in the embodiment shown in Figs. 10-13 and Fig. 21, which comprises the built in electromagnet 24 for locking the rotor of the eddy current brake 15 when energised. This also means that the electromagnet 32 and the anchor plate 31 used in Fig. 20 is dispensed with in Fig. 22. Electric power is supplied to the built in electromagnet 24 via a cable 37 shown in Figs. 21 and 22.

In Fig. 24 the sliding door 28 is normally retained in its open position by means of the electromagnet 32, which is mounted on the door frame. When energised the electromagnet attracts the anchor plate 31, which is connected to the free end of a wire 33, and which may co-operate with a carrier member 36 mounted on the door 28 as previously described. Thus, when the electromagnet 32 is energised the door may freely be moved between open and closed positions. The door 28 is biased towards its closed position by means of a weight 35, which is connected to the door 28 by means of the wire 33 being passed over a pulley 38. As best shown in Fig. 23, the speed control device 10 embodied as shown in Figs. 1 and 2 is releasably connected to the upper end of the weight 35, for example by means of screws or bolts. The speed control device may then function in a manner similar to that described in EP 0 530 425. When the supply of electric power to the electromagnet 32 is interrupted, for example in case of fire, the anchor plate is released and moved to the right in Fig. 24 under the influence of the bias of the weight 35. The anchor plate then comes into engagement with the carrier member 36, whereby the door is moved to its closed position, the speed of movement being controlled by the device 10.

Fig. 25 shows a modification of the arrangement illustrated in Fig. 24. In Fig 25 the anchor plate 31 is connected directly to the door 28 so that the door is maintained in its open position, when the electromagnet 32 is energised, and one end of the wire 33 is also connected to the door such that the door is moved to its closed position under the bias of the weight 35, when the supply of electric power to the electromagnet 32 is interrupted.

Figs. 26-27 illustrate an arrangement in which a speed control device 10 as embodied in Figs. 4-6 is used. The device 10 is mounted on the upper part of the door frame opposite to the door 28 in its open position. An idle pulley 39 is mounted on the frame of the device 10 or adjacent thereto on the door frame. Another idle pulley 40 is mounted on the door frame on the side of the door opening opposite to the pulley 39. One free end of a wire length 41 is passed over the pulley 39 and connected to a vertically movable biasing weight 35. By means of a connecting member 42 the other free end of the wire length 41 is connected to an endless wire 33, which is passed over the idle pulley 40 and over the pulleys 17 and 21 (Figs. 4-6) within the device 10 as best shown in Figs. 26 and 27. An enlargement or a dog 43 for co-operating with a carrier member 36 mounted on the door 28 is fixedly positioned on an upper run of the endless wire 33. The upper and lower runs of the endless wire 33 are passed trough corresponding holes in the carrier member 36 as shown in Fig. 28. When the electromagnet 24 (Figs. 4-6) built into the device 10 is energised the rotor of the eddy current brake 15 and, consequently, also the reversing pulley 17 are locked, so that the endless wire 33, the wire length and the weight 35, which is in its upper position, can not move. However, the door 28 may freely be moved between its open and closed positions. When for some reason the supply of electric power to the electromagnet 24 inside the device 10 is interrupted the rotor of the brake 15 is released and the wire length 41 is moved downwardly under the bias of the weight 35. Thereby the endless wire 33 is moved such that the dog 43 is moved into engagement with the carrier member 36, and the door 28 is moved to its closed position controlled by the speed control device 10.

Fig. 29 illustrates an arrangement similar to that shown in Fig. 28. However, in Fig. 29 the device 10 is the embodiment shown in Fig. 3, and the arrangement is adapted to a sliding door closing in a direction opposite to the closing direction in Fig. 28.

As illustrated by the examples described above, the same basic speed control device 10 may - with a few minor and rather cheap modifications - be used for a large number of different security arrangements for sliding doors, so that most specific requirements encountered in practise may be met. For those skilled in the art it is apparent that a large number of other combinations and modifications than those described may be made so that other demands met in the market may be fulfilled by using one and the same basic structure of the speed control device.

Claims

A method of making arrangements for controlling the closing movement of a sliding door, which is movable between open and closed positions and biased from its open towards its closed position, when a releasable retaining device is released, said arrangement including a speed control device having a frame, braking means with a rotor rotatably mounted on the frame, a wire and pulley drive drivingly connected to the door and to the rotor such that the rotor is rotated when the door is moved into its closed position due to release of the retaining device, said method comprising the use of such speed control device in at least two of the following manners:

(a) connecting or engaging one end part of the wire to the door, passing the wire around a guide pulley arranged at the side of the door opening opposite to the door in its open position, stationarily fastening an other end part of the wire, and suspending the speed control device in a wire loop formed between the guide pulley and said other end of the wire, whereby the control device forms at least part of a biasing weight,

(b) fastening the frame of the speed control device stationarily at one side of the door opening opposite to the door in its open position and connecting or engaging one end part of the wire to the door and another end part to a weight for biasing the door towards its closed position, when the releasable retaining device is released,

(c) fastening the frame to the upper part of the door, which is slidable along a supporting rail being inclined so as to bias the door towards its closed position by its own weight, and connecting opposite end parts of the wire to stationary building parts, such that the wire extends along said rail.
A method according to claim 1, wherein the speed control device is used in all three manners (a), (b) and (c).
A method according to claim 1 or 2, wherein the frame of the speed control device is fastened stationarily at one side of the door opening opposite to the door in its open position and a dog or carrier is connected to the wire, the dog or carrier being adapted to engage with the door and move it towards its closed position when the retaining means are released, and connecting another part of the wire to a weight for biasing the dog or carrier into engagement with the door for moving the same.
A method according to any of the claims 1-3, comprising fastening to the wire a dog or carrier adapted to engage with the door and move it towards its closed position when the retaining means are released, the wire being passed around a guide pulley arranged at the side of the door opening opposite to the door in its open position, and stationarily fastening an end part of the wire, and suspending the speed control device in a wire loop formed between the guide pulley and said stationarily fastened end part of the wire, whereby the control device forms at least part of a biasing weight for biasing the dog or carrier and, consequently, the door towards its closed position when the retaining means are released.
A method according to any of the claims 1-4, wherein the frame of the speed control device comprises a substantially closed housing containing the rotor of the braking means and first and second mutually spaced pulleys of the wire and pulley drive.
A method according to claim 5, wherein the housing comprises first and second housing parts carrying the first and second pulleys, respectively, said first and second housing parts being mutually hinge connected.
A method according to claim 6, wherein the axis of the hinge connection extends substantially parallel with the rotational axis of said first pulley.
A method according to any of the claims 5-7, wherein the housing is substantially parallelepiped shaped.
A method according to any of the claims 1-8, wherein the braking means comprise an eddy current brake having a rotor, which is driven by the first pulley via meshing gearwheels, one of said gearwheels being mounted on its shaft by means of an overrunning clutch or similar means transmitting the rotational movement of the first pulley to the brake rotor in one rotational direction only.
A method according to any of the claims 1-9, wherein the speed control device forms part of a biasing weight, and said pulleys of the wire pulley drive comprising a wire reversing pulley rotatably mounted on the frame and having a peripheral, circular groove or track formed therein for receiving said wire and defining a first plane, a guide pulley being rotatably mounted on the frame above the reversing pulley and defining a circular groove or track therein defining a second plane, which defines an acute angle with said first plane, whereby the wire may be passed around the reversing pulley and into engagement with opposite sections of the guide pulley such that the wire parts extending between the pulleys are mutually crossing without contacting each other.
A method according to any of the claims 1-10, wherein the door is held in its open position by electromagnetic forces, the biasing means being activated by disrupting an electric current generating the electromagnetic forces.
A method according to claim 11, wherein the electromagnetic forces are blocking the rotational movement of the rotor of the braking means or other rotatable elements drivingly connected therewith.
A method according to claim 12, wherein the rotor of the braking means is held stationary by an electromagnet.
A method according to claim 13, wherein the electromagnet is positioned spaced from the centre axis of the rotor.
A method according to any of the claims 12-14 when using manner (c) or (e), wherein the part of the wire and pulley drive on which the carrier or dog is mounted, is formed into a closed loop, which is passed around a guide pulley at one side of the door opening opposite to the frame of the speed control device.
An arrangement for controlling the closing movement of a sliding door, which is movable between open and closed positions, said arrangement comprising
biasing means for biasing the door towards its closed position, releasable retaining
means for retaining the biasing means in an inactive condition,
a speed control device having a frame, braking means with a rotor rotatably mounted on the frame, a wire and pulley drive drivingly connected to the door and to the rotor so that the rotor is rotated when the door is moved from its open to its closed position, the retaining means comprising an electromagnetic device, which is positioned adjacent to the rotor of the braking means and adapted to block the rotational movement of the rotor and other rotatable elements drivingly connected therewith, when energised.
An arrangement according to claim 16, wherein the electromagnetic device is spaced from the central axis of the rotor.