EP1724431A1

EP1724431A1 - Door arrangement comprising a tension system and method of operating such tension system

Info

Publication number: EP1724431A1
Application number: EP05010754A
Authority: EP
Inventors: Bo Fransson
Original assignee: Cardo Door AB
Current assignee: Cardo Door AB
Priority date: 2005-05-18
Filing date: 2005-05-18
Publication date: 2006-11-22

Abstract

The invention discloses a door arrangement (1) comprising a flexible door leaf (2), arranged on a winding roller (3), wherein the door arrangement (1) is provided with flexible traction members (4) associated with at least one driving device (5) for applying a traction force on the flexible door leaf (2) in order to enable the flexible door leaf (2) to be movable between a closed position and an open position, and vice versa. The door arrangement (1) comprising a tension system (6) comprising said flexible traction members (4) extending along the directions of movement, and said tension system forming (6), at the sides of the door arrangement (1), a closed loop system. Furthermore, a first and a second resilient element (7, 8) are provided to said tension system (6) on either side of a lower portion (24) of said flexible door leaf (2) as seen when following said closed loop system from at least one direction and said first resilient element (7) is resilient within a tension range (A-B) such that, during stalling, tensioning of said first resilient element (7) is limited to a threshold value by a holding element (17).

Furthermore, the invention discloses a method for operating such a door arrangement (1) during stalling of said door leaf (2).

Description

Field of the Invention

The present invention relates to a door arrangement comprising a flexible door leaf, arranged on a winding roller, wherein the door arrangement is provided with flexible traction members associated with at least one driving device in order to enable the flexible door leaf to be movable between a closed position and an open position, and vice versa, said door arrangement comprising a tension system comprising said flexible traction members extending along the directions of movement, and said tension system forming, at the sides of the door arrangement, a closed loop system.

Technical Background

There exist in the art various roller door arrangements provided with flexible traction members. US 4,997,022 discloses a roller door provided with a flexible door leaf, wound on a winding roller and provided with a flexible traction member. Such tension system of a door arrangement will provide necessary force to the flexible door leaf during opening and closing operations as well as maintain it in a taut condition when closed.
However, a door arrangement comprising a flexible door leaf and flexible traction members in a closed loop system, maintained in tension by at least one resilient element, may experience damage during an unintentional stop. This damage may for example occur when the door leaf is hindered in its movement between an open and a closed position, or vice versa and result in wearing of in particular said resilient element if repeated over time.
Furthermore, demands on particularly industrial door arrangements are increasing. If the door leaf for any reason is obstructed or stalled in its movement between an open position and a closed position, and vice versa, for example by wind loads causing friction. A slack in the tension system will arise if the winding roller continues to feed the flexible door leaf/flexible traction member. This may lead to jamming or obstruction of the flexible door leaf at the winding roller.
If a slack arises in the flexible door leaf during its movement from an open to a closed position or vice versa, the surface exposed to the wind will increase and hence the wind load. Thereby, the stalling force may increase due to friction. In order to overcome the friction causing the resistance in the closing or opening of the door arrangement, more force has to be used and consequently a more powerful driving device has to drive the winding roller. A more powerful driving device consumes more energy, which gives several negative implications.
Hence, there is a need for an improved roller door arrangement, provided with a closed loop system, capable of handling slack during normal operation, as well as if unintentionally stalled during movement. It is a further issue to provide an improved roller door arrangement with a persistent tension system adapted for safe and secure operation over a long period of time. It is a more general object of the invention to provide a door arrangement capable of handling stalling of the door leaf and slack of the tension system smoothly and yet with a reasonable effect requirement on the driving device.

Summary of the Invention

These and other objects are achieved by a method and a door arrangement according to the respective independent claims. Preferred methods and embodiments of the invention are defined in the dependent claims.
According to the invention a method for handling slack in a door arrangement is presented, said door arrangement comprising a flexible door leaf arranged on a winding roller, if said flexible door leaf is stalled in its movement between an open and a closed position, or vice versa, said door arrangement being provided with flexible traction members associated with at least one driving device for applying a traction force on the flexible door leaf in the direction of movement, said door arrangement comprising a tension system comprising said flexible traction members and said tension system forming, at the sides of the door arrangement, a closed loop system, wherein a first and a second resilient element are provided to said tension system on either side of the lower portion of said flexible door leaf as seen when following the closed loop in one direction, said method comprises the steps of:

applying a traction force on the flexible door leaf,
during stalling of said flexible door leaf the tensioning of one of said resilient elements increases until a threshold value of said resilient element tension range is reached,
providing holding of said resilient element when said threshold value is reached,
effecting a tension compensating effect of the other resilient element of said tension system.

The first and second resilient element are provided to said tension system on either side of a lower portion of said flexible door leaf. The driving device applies a traction force on the door leaf by means of the flexible traction members. Suitably, said door leaf forms part of said closed loop tension system. The flexible traction members are then possibly integrated in the door leaf. Alternatively, said door leaf functions as flexible traction member throughout a zone and being connected to flexible traction members by its end portions.
During operation, the closed loop system utilizes a winding roller and a roll-up winder, which may be on the same or on separate axles and the dimensions of the two rollers change during the closing and opening movement, hence giving origin to certain irregularities in the winding process. Other reasons for irregularities in the winding process may also occur. Thus, it is important with resilient elements that are able to handle these irregularities and maintain the closed loop system in a tensioned state during opening and closing of the door arrangement, and prevent slack in the closed loop system.
During operation the driving device applies a traction force on the door leaf by means of the flexible traction members. If the door leaf is stalled meaning in the content of this application any situation where the friction force during movement result in a slack of the tension system or part of the tension system and in particular when the movement of the door leaf is temporarily or completely stopped due to a counteracting force. It is preferred that the system continues to apply the traction force to overcome the force by which the door leaf is stalled. The first resilient element will, in the situation where the door leaf is stalled in a closing movement, be tensioned by the traction force applied by the traction members. Hence, the traction force applied on the door leaf will be lower than if the traction member did not have a resilient element.
However, the arrangement with a determined tension range and a hard stop being reached when the tension range is reached provides the first resilient element to become stiff in that particular direction, and hence the traction force is applied directly on the door leaf. By using the full operator force, the arrangement thereby provides for the stalling force to be overcome smoothly and with less force being provided from the driving device than in an arrangement without a given tension range.
A situation where the door leaf is stalled in its movement between a closed and an open position, and vice versa, is more likely to arise in a door arrangement where the door leaf is guided in its movement between an open and a closed position, and vice versa, along a guide, guide rail or the like. Hence, the method according to claim one is therefore readily used in such door arrangements.
Moreover, if the stalled condition is caused by a side impact force, in particular wind, and the driving device keeps feeding the tension system a slack may arise in the tension system and resulting in a potential slack of the flexible door leaf. The slack of the door leaf will increase the area exposed to e.g. wind load and thus the stalling force may increase if there is no means for handling such slack.
In the case were the driving device works for a closing operation of the door arrangement such slack will be compensated by the second resilient element provided in close arrangement with said winding roller. In the case were the driving device works for an opening operation of the door arrangement such slack will compensated by the first resilient element provided in close arrangement with the lower portion of said door arrangement.
Suitably, the door arrangement is arranged so that the first resilient element is attached to a pulley operatively connected to said closed loop flexible traction member.
This arrangement provides for the first resilient element to be positioned in substantially the same position in the arrangement during a closing or opening movement of the flexible door leaf. Hence, the first resilient element will not move along the path of the flexible traction member. The first resilient element can therefore be positioned where it best fulfils the functions of keeping the flexible traction member in a tensioned state, but also becomes inelastic if a certain tension range is exceeded.
Preferably, the flexible traction member propagates around three pulleys. A first pulley, the second tensioned pulley and a third pulley.
In addition to the above described advantages with the inventive door arrangement it is realized that the arrangement with three pulleys forces the traction member to follow a certain path around these pulleys.
Preferably, the upper value of the tension range allowed for the first resilient element is reached when the door arrangement is in its closed position. The first resilient element will be subject for tension during a closing and opening movement, even if the door leaf is not stalled in its movement. If the upper value of the tension range is lower than the maximum tension characteristic of the first resilient element during normal use, the flexible traction members will be applying direct traction force on the door leaf in a normal closing or opening movement, which is not desired from an operating viewpoint. If the upper limit of the tension range is higher than the tension value when the door is in its closed position, problems will arise with ensuring the full closing of the door leaf.
Preferably, the first resilient element is a spring. Although, many options are possible for accomplishing the first resilient element that will fall within the scope of protection, a spring is the currently preferred option.
Suitably, when using a spring as the first resilient element, a spring retainer is used to provide the hard stop to be reached when the tension range is exceeded.
A spring retainer can be constructed in many several ways falling within the scope of protection. However, a chain provided along the propagation of a spring, preferably a spiral spring is one currently preferred alternative.
The second resilient element is preferably operatively connected to said winding roller. In a closing or opening movement of the door leaf, the second resilient member is then operable in handling irregularities in the traction force applied by the flexible traction members.
According to a preferred embodiment the second resilient member is arranged circumferentially along the longitudinal extension of the axle of the winding roller, the axle of the winding roller being spring loaded and provided with a circumferential shoulder and the shoulder being engagable with a stop arranged inside the winding roller.
This arrangement allows for the second resilient member to handle the irregularities in the traction force applied on the door leaf by the flexible traction members. It possibly also allow the second resilient member, in a situation where the door leaf is stalled in its movement between an open and a closed position, to stop feeding the flexible door leaf, i.e. maintain the door leaf in a stretched position. The prevention of slack in the door leaf minimises the surface of the door leaf being exposed to the wind. Hence, the stalling forces to be overcome by the door arrangement, by the driving device, via the traction member are substantially lower. Thereby, the wind loads can be handled by this inventive door arrangement by means of a leaner driving device.
According to a preferred embodiment the second resilient element is a torsion spring, preferably a spiral spring.

Brief Description of the Drawings

A currently preferred embodiment of the present invention will now be described in more detail, with reference to the accompanying drawings.
Fig. 1 is a schematic perspective view of a door arrangement, in an open position, according to a first embodiment of the invention.
Fig. 2a is a partial schematic perspective view from one side of a door arrangement, in an open position, according to a first embodiment of the invention.
Fig. 2b is a partial schematic perspective view from one side of a door arrangement, in a stalled position, according to a first embodiment of the invention.
Fig. 2c is a partial schematic perspective view from one side of a door arrangement, in a closed position, according to a first embodiment of the invention.
Fig. 3a is a schematic side view of a tension system of the first embodiment in accordance with fig 2.
Fig. 3b is a schematic side view of a tension system according to a second aspect of the door arrangement.
Fig. 3c is a schematic side view of a driving arrangement according to a third aspect of the door arrangement.
Fig. 4 is a front view of a first resilient element and a pulley, according to a first embodiment of the invention.
Fig. 5 is a partial schematic perspective view of a winding roller drum.

Detailed Description of Preferred Embodiments

A first embodiment of the invention related to the roller door arrangement will be described in more detail in the following with reference to the accompanying drawings.
Referring now to Fig. 1, wherein a roller door arrangement 1 comprises a flexible door leaf 2, wound on a winding roller 3 which is mounted rotatably at the door opening. The roller door arrangement 1 is provided with flexible traction members 4 associated with at least one driving device 5 for applying a traction force on the flexible door leaf 2, to enable the flexible door leaf 2 to be movable between a closed position and an open position.
In fig 2 a roller door arrangement 1 comprises a detector 22 and security device 23 for interrupting closing movement when an obstacle is detected. Furthermore, the roller door arrangement 1 comprises a lower bar 24 with a detector 22 for detecting an obstacle and possibly interrupting closing movement. The first and second resilient element are provided to said tension system on either side of a lower portion of said flexible door leaf. The driving device applies a traction force on the door leaf by means of the flexible traction members. During operation, the closed loop system utilizes a winding roller and a roll-up winder, which may be on the same or on separate axles and the dimensions of the two rollers change during the closing and opening movement, hence giving origin to certain irregularities in the winding process. Other reasons for irregularities in the winding process may also occur. Thus, the resilient elements are able to handle these irregularities and maintain the closed loop system in a tensioned state during opening and closing of the door arrangement.
During operation the driving device 5 applies a traction force on the door leaf 2 by means of the flexible traction members 4. If the door leaf 2 is stalled meaning in the content of this application any situation where the friction force during movement result in a slack of the tension system or part of the tension system and in particular when the movement of the door leaf is temporarily or completely stopped due to a counteracting force. It is preferred that the tension system continues to apply the traction force to overcome the force by which the door leaf is stalled. The first resilient element 7 will, in the situation where the door leaf is stalled in a closing movement, be tensioned by the traction force applied by the traction members. Hence, the traction force applied on the door leaf 2 will be lower than if the traction member 4 did not have a resilient element. However, the door arrangement with a determined tension range and a hard stop being reached when the tension range is reached provides the first resilient element 7 to become stiff in that particular direction, and hence the traction force is applied directly on the door leaf 2. By using the full operator force, the arrangement thereby provides for the stalling force to be overcome with less force being provided from the driving device 5 than in a door arrangement 1 without a given tension range.
A situation where the door leaf 2 is stalled in its movement between a closed and an open position, and vice versa, is more likely to arise in a door arrangement where the door leaf is guided in its movement between an open and a closed position, and vice versa, along a guide, guide rail or the like. Hence, the arrangement according to claim one is therefore readily used in such door arrangements 1.
Moreover, if the stalled condition is caused by a side impact force, in particular wind, and the driving device 5 keeps feeding the tension system a slack may arise in the tension system and resulting in a potential slack of the flexible door leaf. The slack of the door leaf will increase the area exposed to e.g. wind load and thus the stalling force may increase if there is no means for handling such slack.
According to the invention and in the case were the driving device works for a closing operation of the door arrangement such slack will be compensated by the second resilient element provided in close arrangement with said winding roller 3. In the case were the driving device works for an opening operation of the door arrangement such slack will compensated by the first resilient element provided in close arrangement with the lower portion of said door arrangement.
Suitably, the door arrangement is arranged so that the first resilient element 7 is attached to a pulley 14 operatively connected to said closed loop flexible traction member 4.
This arrangement provides for the first resilient element 7 to be positioned in substantially the same position in the door arrangement during a closing or opening movement of the flexible door leaf. Hence, the first resilient element 7 will not move along the path of the flexible traction member. The first resilient element 7 can therefore be positioned where it best fulfils the functions of keeping the flexible traction member in a tensioned state, but also becomes inelastic if a certain threshold value is reached.
Preferably, the flexible traction member propagates around three pulleys. A first pulley 15, the second tensioned pulley 14 and a third pulley 16.
In addition to the above described advantages with the door arrangement 1 it is realized that the arrangement with three pulleys forces the traction member to follow a certain path around these pulleys.
Preferably, the upper value (B) of the tension range allowed for the first resilient element 7 is reached when the door arrangement is in its closed position. The first resilient element 7 will be subject for tension compensating operations in the tension system 6 during a closing and opening movement, even if the door leaf is not stalled in its movement.
If the upper value of the tension range were to be lower than the maximum tension characteristic of the first resilient element during normal use, the flexible traction members will be applying direct traction force on the door leaf in a normal closing or opening movement, which is not desired from an operating viewpoint. If the upper limit of the tension range were to be higher than the tension value when the door is in its closed position, problems will arise with ensuring the full closing of the door leaf.
With reference to fig 3a the driving function of a first embodiment of the door arrangement will be described. The winding roller 3 is integrally rotatably connected to a second drum on which is wound, in contrary direction to the flexible door leaf 2, the flexible traction member 4, said flexible traction member 4 describing a path from said winding roller 3 via one first pulley 15 at the base of the door opening via a tensioning pulley 14 and a third pulley 16 to said second drum. The second drum is arranged to a driving axis of said driving device 5. According to a preferred embodiment each side of the flexible door leaf has a flexible traction member 4 connected thereto and arranged along the longitudinal direction thereof. The flexible traction member 4 is of belt type.
With reference to fig 3b a driving function of a second aspect of the door arrangement will be described schematically. A winding roller 103 is connected to a shaft associated rotatably to a driving device forming part of said driving device 5. On said winding roller 103 the flexible door leaf 2 is wound. A flexible traction member describes a path from said winding roller 103 around at least one pulley 115 at the base of the door opening via a tensioning pulley 114 and a third pulley 116 to a second winding roller 127 arranged on the same shaft as the winding roller 103 but preferably to an outer side of the door leaf. Hence, the path of the flexible traction member is preferably arranged with an angle during at least one part of the path as can be seen from an other direction. The driving device 5 and hence the winding rollers 103, 127 is able to move along with a forward and backward motion.
Fig 3c discloses schematically a third aspect of the driving device of the door arrangement. A winding roller 203 is connected to a shaft associated to a driving device forming part of said driving device 5. On said winding roller 203 the flexible door leaf 2 is wound. A flexible traction member describes a path from said winding roller 203 around at least one tensioned pulley 214 at the base of the door opening to a second winding roller 227 arranged on the same shaft as the winding roller 203 but preferably to an outer side of the door leaf. Hence, the path of the flexible traction member is preferably arranged with an angle during at least one part of the path as can be seen from an other direction. Either of the first and second winding rollers 203, 227 has a drum comprising a spring. Alternatively, the outer winding roller 227 comprises a conical drum making it possible to maintain the flexible traction member in a stretched condition during winding operations. Conveniently, a reversible driving device is used as indicated by the arrow.
Various principles for performing a secure and safe operation of the door arrangement have been illustrated in fig 3a-3c. It is realized that the listed concepts may be further varied without departing from the scope of protection. Furthermore, a secure and safe operation is accomplished with any aspect of the above disclosed door arrangements using any suggested path of the flexible traction member on both sides of the door.
Now with reference to fig 4 a more detailed description of a first resilient element 7 will be provided. The first resilient element 7 is a spring. Although, many options are possible for accomplishing the first resilient element that will fall within the scope of protection, a spiral spring is the currently preferred option. Suitably, when using a spring as the first resilient element 7, a spring retainer 17 is used to provide a holding effect when a threshold value is reached.
A chain provided along the propagation of a spring, preferably a spiral spring is one currently preferred alternative for a spring retainer 17. Furthermore, the tension in the tension system is adjustable by manipulating a screw 19 or similar in order to adjust the distance between the pulley and the spiral spring of the first resilient element. More preferably, said first resilient element 7 is stiffer than said second resilient element 8.
With reference to fig. 5 the function of a preferred second resilient element is described in more detail . The second resilient element 8 is preferably operatively connected to said winding roller 3. In a closing or opening movement of the door leaf, the second resilient element 8 is then operable in handling irregularities in the traction force applied by the flexible traction members.
According to a preferred embodiment the second resilient element 8 is arranged circumferentially along the longitudinal extension of the axle 10 of the winding roller. The resilient element is held fix to said axle 10 inone end portion by a first engaging element 13. The other end of the second resilient element 8 is connected to a second engaging element 11 which is able to pivot between and within a range defined by a first and second position (C-D). The second engaging element 11 is provided with a shoulder being engagable with a stop 12 arranged inside a drum of the winding roller and the two sides of said stop 12 provides the first and second position (C-D) of the tension range. Thus the axle 10 of the winding roller being spring loaded within a tension range.
This arrangement allows for the second resilient element to handle the irregularities in the traction force applied on the door leaf by the flexible traction members. It does also allow the second resilient member, in a situation where the door leaf is stalled in its movement between an open and a closed position, to stop feeding part of the door leaf and thereby prevent slack in the door leaf, i.e. maintain the door leaf in a stretched position. The prevention of slack in the door leaf minimises the surface of the door leaf being exposed to the wind.
It is realised by a person skilled in the art that the invention is not limited to the various preferred embodiments described above and shown in the accompanying figures, but that many other variants may still be envisaged without moving beyond the scope of the present invention.
A closed loop system for a flexible traction member is understood to mean a flexible traction member that has, either mechanically or electrically, an operative connection between the rollers or drums onto which the flexible traction member is wounded or unwounded.
The flexible traction member can be a belt, rope, chain or any other member able to fulfil the same operative function.
According to a preferred embodiment the winding roller is integrally rotatably connected to a second drum on which is wound, in contrary direction to the flexible door leaf, the flexible traction member, said flexible traction member describing a path from said winding roller around at least one guide roller at the base of the door opening via a tensioning roller to said second drum. Each side of the flexible door leaf has a flexible traction member connected thereto and arranged along the longitudinal direction thereof.
Preferably, the flexible traction member is a belt. Alternatively, the flexible traction member is a rope, a wire, a cable. Other flexible traction members of various materials may be used as long as they are suitable for transfer a pulling force. Hence, a pulling force is provided to an elongated flexible traction member in the propagating direction of the flexible traction member. This allows for a driving function almost integered in the door leaf which makes the winding of the roller door easy and stable.
The term "flexible door leaf" should be understood to mean, within the context of this invention, any flat element able to form a closure or a separation and able to roll around an axis or to be folded, such as an awning, a strip of plastic material, etc., intended for closing a bay, forming a separating partition.

Claims

A method for handling slack in a door arrangement, (1) comprising a flexible door leaf (2) arranged on a winding roller (3), if said flexible door leaf (2) is stalled in its movement between an open and a closed position, or vice versa,
said door arrangement being provided with flexible traction members (4) associated with at least one driving device (5) for applying a traction force on the flexible door leaf (2) in the direction of movement,
said door arrangement comprising a tension system (6) comprising said flexible traction members (4) and said tension system (6) forming, at the sides of the door arrangement (1), a closed loop system, wherein a first and a second resilient element (7, 8) are provided to said tension system (6) on either side of the lower portion (24) of said flexible door leaf (2) as seen when following the closed loop in one direction, said method comprises the steps of:
- applying a traction force on the flexible door leaf (2),

- during stalling of said flexible door leaf (2) the tensioning of one of said resilient elements (7, 8) increases until a threshold value of said resilient element tension range is reached,

- providing holding of said resilient element when said threshold value is reached,

- effecting a tension compensating effect of the other resilient element of said tension system.
The method according to claim 1, in which said threshold value of said first resilient element (7) tension range is reached when said flexible door leaf (2) is in its fully closed position during normal operation.
The method according to any one of claims 1-2, in which the step of adjusting slack in at last part of said tension system (6), if said flexible door leaf (2) being stalled during closing operation movement, comprising effecting a tension release of one of said resilient elements (7, 8) resulting in a stretch in the near part of said tension system (6).
The method according to any one of claims 1-3, further comprising effecting a tension compensating effect of said second resilient element (8) within a tension range, said step being enabled in that said winding roller (3) comprising a spring loaded axle (10) forming part of said second resilient element (8), which spring loaded axle (10) being provided with a first engaging portion (11) capable of pivoting between a first and second position (C, D), said positions defining said tension range.
The method according to claim 4, in which said pivoting of said first engaging portion (11) between said first and second positions (C, D) results in a stretch of said tension system (6) which substantially equals the double distance of the full tension range (A, B) of said first resilient element (7).
A door arrangement (1) comprising a flexible door leaf (2), arranged on a winding roller (3), wherein the door arrangement (1) is provided with flexible traction members (4) associated with at least one driving device (5) in order to enable the flexible door leaf (2) to be movable between a closed position and an open position, and vice versa, said door arrangement (1) comprising a tension system (6) comprising said flexible traction members (4) extending along the directions of movement, and said tension system forming (6), at the sides of the door arrangement (1), a closed loop system
characterized in that
a first and a second resilient element (7, 8) are provided to said tension system (6) on either side of a lower portion (24) of said flexible door leaf (2) as seen when following said closed loop system from at least one direction and said first resilient element (7) is resilient within a tension range (A-B) such that, during stalling, tensioning of said first resilient element (7) is limited to a threshold value by a holding element (17).
Door arrangement (1) according to claim 6, wherein said first resilient element (7) comprises a tensioned pulley (14) operatively connected to said tension system (6) .
Door arrangement (1) according to claim 7, wherein said flexible traction member is linked via a first pulley (15), said tensioned pulley (14) and a third pulley (16), said first and third pulley being arranged lower than said tensioned pulley (14).
Door arrangement (1) according to any one of claims 6-8, wherein said threshold value (B) of said first resilient element tension range (A-B) is reached when said flexible door leaf (2) is in its fully closed position during normal operation.
Door arrangement (1) according to any one of claims 6-9, wherein said first resilient element (7) is a spiral spring and said holding element (17), preferably of chain type, is provided along the propagation of said spiral spring.
Door arrangement (1) according to any one of claims 6-10, wherein said second resilient element (8) is operatively connected to said winding roller (3).
Door arrangement (1) according to any one of claims 6-11, wherein a winding roller (3) comprising a spring loaded axle (10), forming said second resilient element (8) and being adapted to cause a tension compensating effect of said second resilient element (8) within a first position (C) and a second position (D).
Door arrangement (1) according to any one of claims 6-12, wherein said second resilient element (8) is a torsion spring, preferably a spiral spring, arranged along said axle.