This application is a 371 of PCT/EP2016/070845, filed on Sep. 5, 2016, published on Mar. 23, 2017 under publication number WO 2017/045954, which claims priority benefits from Swedish Patent Application No. 1551190-0, filed on Sep. 16, 2015, the disclosure of which is incorporated herein by reference.
The present invention concerns motorized doors and gates comprising a shutter for closing or opening an area defined by a frame. The present invention proposes a door capable of reducing the force of any impact of the closing leading edge with a body as well as when contacting an end position of the shutter. In particular, it concerns motorized doors provided with detection cells suitable for detecting the presence of a body within the closing trajectory of a leading edge of said shutter.
Motorized doors or gates (both terms being used herein as equivalent) comprising a shutter are commonly used to shut off openings, particularly in warehouses, supermarkets, or industrial halls. These shutters are often made up of large flexible tarpaulins the lateral edges of which comprising beads (1B) which slide in guiding rails (4) situated on each side of the opening that is to be closed. Alternatively, they can be made of rigid panels hinged to one another side by side or the shutter can be a rigid panel. Automatic doors are particularly useful when they are used to separate two spaces having different environmental conditions, such as temperature, relative humidity and the like, and more particularly to separate an indoor space from outdoor. Doors able to open and close at high speed are also known for these applications and are often referred to as “fast doors”.
One issue with motorized doors, particularly with fast doors due to their high closing speeds, is impacts with obstacles accidentally located within the closing trajectory of the shutter. Besides damaging the leading edge of the shutter and also disengage the bead of the shutter lateral edges from the guiding rail, the obstacle itself can be damaged. Considering that such obstacle can be a person, the danger in case of an impact of injuring said person is quite high and must be reduced. For this reason, strict norms have been imposed on motorized doors. For example, in order to comply with the European norm EN12453, the peak force of an impact with a body must not exceed the limit of 150 N during more than 5 s, and must not exceed the limit of 400 N during more than 0.75 s.
In order to meet these severe requirements, the leading edges of motorized doors are often equipped with damping elements, such as a lip made of a resilient material, or pneumatic absorbing pistons. For most doors, in particular fast doors, which have a high kinetic energy, such damping elements reduce the impact force in case of impact, but not sufficiently to meet the requirements of EN12453. Many doors are therefore additionally or alternatively provided with detection cells.
An accidental event detection cell can comprise contact detectors as disclosed for example in US2007/0261305. Alternatively, some detection cells are based on the comparison with a reference value of parameters such as the motor torque, motor energy consumption, or shutter closing speed, such as in U.S. Pat. No. 5,198,974. Such detection cells, however, identify the occurrence of an impact only after the leading edge has contacted the obstacle, which is of limited use for a person being hit by the leading edge of a closing shutter.
Since preventing is better than repairing, many motorized doors have been developed comprising (a) contactless detection cells suitable for detecting the presence of an obstacle within the closing trajectory of a shutter before an impact occurs, and (b) a control system programmed for implementing a safety function aimed at managing the accidental presence of obstacles, in particular by stopping the door in its travel when it encounters one and moving it away from the obstacle in order to allow the removal thereof.
Various types of such contactless detection cells are known in the art, such as in U.S. Pat. No. 7,034,686 disclosing a proximity detector provided with an antenna, which triggers a command to stop and reverse the closure of the vertical door when the magnetic field created by the antenna is disturbed by a foreign object. This system has the advantage of preventing an impact, but it has the drawback of lacking precision given that the magnetic field may radiate outside the closure plane and thus cause false alarms triggered by objects situated close to the door but not underneath it. Optical, ultrasonic and radar sensors are also available which are able to detect the presence of a foreign body within the trajectory of the shutter. A person skilled in the art therefore has a selection of detection cells to choose from for detecting an accidental event.
Once an obstacle has been detected, a safety function must be triggered. In particular, such safety function almost always includes stopping the closing motion of the shutter and sometimes comprises reversing the direction of the motion to re-open the shutter. For example, U.S. Pat. Nos. 7,034,682, 6,989,767, 5,198,974 and US2007/0261305 disclose safety systems for doors in which, as soon as an accidental event is detected, the motor stops, reverses its direction of rotation in order to open the door completely and stops definitively when the door is completely open. The door can be closed once again by manual intervention.
The detection cells and control systems of the art cannot identify the nature of an obstacle and would treat any identified object as an accidental obstacle. The shutter is closed when the leading edge contacts a distal transverse edge (for vertically top-down shutters, it generally corresponds to the floor). It is clear that the detection by the detection cells of the approaching distal transverse edge should not be treated as an accidental obstacle, triggering the stopping of the shutter. At the same time, the impact force between the leading edge and the distal transverse edge shall remain moderate. There are systems able to determine the instant position of the leading edge. For example, some systems count the number of revolutions of the motor to estimate the position of the leading edge. Though very simple, this system is not very reliable, at least when the shutter is a flexible shutter rolled up around a drum, because at each revolution of the drum, the length of shutter being delivered varies as a function of the diameter of the drum. A more sophisticated system uses optical sensors counting the number of specific markers provided at regular intervals on longitudinal edges of the shutter (transverse to the leading edge) which pass in front of said optical sensors. Such systems are much more reliable than the former one, but all doors are not necessarily provided with such systems, which cannot be added easily to a standard door. Furthermore, there are situations, wherein such position detection systems cannot be used satisfactorily.
For example, it is possible that a raised deck (e.g., the platform of a lorry) be momentarily installed across the door frame to serve as an upper transfer surface for moving goods from one side to the other of the door. In this case, the raised deck shall form a new “momentary distal transverse edge,” where the leading edge shall stop and contact in its closed configuration. A system determining the instant position of the leading edge will be of no use in this case because the CPU would be programmed to run the shutter in the closing direction until the original distal transverse edge, which is positioned further from the momentary distal transverse edge. The CPU would consider the raised deck detected by the detection cells as an accidental obstacle, triggering the stopping of the shutter and, possibly, the reversal of the shutter movement to re-open the shutter.
There therefore remains a need in the art for detection cells and a control system applied to motorized doors, which can distinguish between a body forming an accidental obstacle and a body forming a distal transverse edge defining the final position of the leading edge when the shutter is closed. The present invention provides a motorized door provided with detection cells and a control system (CPU), which avoids any impact of the leading edge of the shutter with a body with an impact force of more than 400 N as defined in EN12453. At the same time, the CPU is able to distinguish between an accidental obstacle and a distal transverse edge, regardless of the position of the latter, and to trigger different actions depending on the nature of the body. The detection cells and control system of the present invention can be implemented on any existing doors with little effort and low cost. This and other advantages of the present invention are presented in continuation.
The present invention is defined in the appended independent claims. Preferred embodiments are defined in the dependent claims. In particular, the present invention concerns a motorized door for closing an area, said area being defined by a first and second lateral edges which extend parallel to a longitudinal axis, X1, by a proximal transverse edge extending parallel to a transverse axis, X2, normal to the longitudinal axis, X1, and a distal transverse edge, transverse to the longitudinal axis, X1, wherein said motorized door comprises:
The safety proportion, Ps, can for example be comprised between 80% and 100%, preferably between 90% and 100%. The array of n detection cells distributed along the leading edge of the shutter may count at least 3, preferably at least 4, more preferably at least 5 detection cells per metre of leading edge measured along the transverse direction, X2. The detection cells can be selected among one or more of the following: ultrasonic sensors, optical sensors, capacitor sensors, radar sensors, or radio-frequency sensors.
The CPU can also be programmed to trigger the following actions in case P≤Ps, and all of the n1 detection cells having detected the presence of a body communicate to the CPU that said body is located at a distance, Δx, greater than the predefined safety distance, Δxs, from each of said detection cells, Δx>Δxs, during the moving in the first direction (α) of the shutter at the service closing speed, v1, from the open position (x1,1) towards the closed position (x1,0):
The service closing speed, v1, is typically comprised between 0.25 and 1 m/s, preferably between 0.5 and 0.8 m/s. The reduced closing speed, v2, can then be comprised between 40% and 80% of v1, preferably between 50% and 75% of v1.
The distance, Δx, the leading edge of a door covers in a closing time, t, can be calculated as the product of the closing speed with closing time, Δx=v1·t. Similarly, the safety distance, Δxs, required for a given application depends inter alia on the closing speed, v1, and can be calculated as, Δxs=v1·timp, wherein timp is a safety impact time required for the leading edge to cover the distance, Δxs, at the service closing speed, v1. The safety impact time, timp, is preferably comprised between 0.5 and 3 s, preferably, between 0.8 and 2 s.
The CPU can also be programmed to trigger the following actions after instantly stopping the movement of the leading edge in the first direction (α), in response to the detection by a proportion, P≤Ps, of detection cells of the presence of an object at a distance Δx≤Δxs:
In a preferred embodiment, the CPU is programmed to repeat the foregoing actions, after instantly stopping (N−1) times the movement of the leading edge in the first direction (α), without reaching the distal transverse edge. If the leading edge is stopped a Nth time, the CPU is programmed to reverse said movement into the second direction (β) until the leading edge reaches the open position (x1,1). The value of N is preferably comprised between 2 and 5 times.
For a fuller understanding of the nature of the present invention, reference is made to the following detailed description taken in conjunction with the accompanying drawings in which:
As illustrated in
As shown in
In case of a vertical area (20) as illustrated in
A motorized door according to the present invention must also comprise an array of n detection cells (s1, s2, . . . , sn), wherein n≥2, distributed along the leading edge of the shutter. Each detection cell is suitable for detecting and communicating to a processing unit (CPU) the presence and distance, Δx, from said detection cell measured along the longitudinal axis, X1, of a body positioned between said detection cell and the distal transverse edge.
The gist of the present invention is the control system, driven by a processing unit (CPU) which is programmed to receive signals from each of the n detection cells, either continuously, or at regular intervals. Energy can be saved by activating the detection cells only when the leading edge is moving in the closing direction, a. For high speed doors, a continuous communication between detection cells and CPU is preferred or, in case of intermittent communication, the frequency of emitted signals should be high, preferably greater than 1 signal per second. When, during the moving in the first direction (α) of the shutter at a service closing speed, v1, from the open position (x1,1) towards the closed position (x1,0), a number n1 of the n detection cells, with n1≥1, communicates to the CPU the detection of the presence of a body located at a distance, Δx, of not more than a predefined safety distance, Δxs, from said detection cell, Δx<Δxs, the CPU is programmed to trigger the following operations depending on the proportion, P=n1/n, of detection cells having detected a body.
In case the proportion, P=n1/n, of detection cells identifying the presence of a body at a same time is not more than a predefined safety proportion, Ps, (P≤Ps) the CPU is programmed to instantly stop the movement of the leading edge in the first direction (α). The CPU may optionally be programmed to then reverse said movement into the second direction (β) to drive the leading edge away from the identified body. This optional reversal of the shutter movement depends inter alia on the value of the safety distance, Δxs: for high values of Δxs, a reversal may not be necessary; for short safety distances, Δxs, a reversal may be advisable.
In case, however, the proportion, P=n1/n, of detection cells identifying the presence of a body at a same time is greater than the safety proportion, Ps, (P>Ps), the CPU is programmed to communicate a signal to progressively reduce the closing speed of the leading edge in the first direction (α), down to a stop upon contacting said body at Δx=0 of the detection cell located closest to said body (cf.
By considering the proportion, P=n1/n, of detection cells identifying the presence of a body at a same time, the CPU is able to “distinguish” between:
This system is highly advantageous, because it requires no metering system capable of determining the instant position of the leading edge. Such systems can be unreliable, for example if counting the number of revolutions of a drum (2) carrying a flexible shutter wound around it, or not readily available or easy to install in existing doors, in case for example of optical sensors counting markers distributed along an edge of the shutter. Furthermore, a metering system is not capable of taking account of a provisional raised deck as illustrated in
By distinguishing between accidental obstacles and distal transverse edges (even if not at a fixed position), by means of the proportion, P=n1/n, of detection cells identifying the presence of a body at a same time, and by considering the closest distance, Δx, of said body from a detection cell with respect to a safety distance, Δxs, a motorized door according to the present invention can be run with a high level of security, in accordance with the requirements of EN12453 and, at the same time smoothly closing an area, contacting the distal transverse edge (20D) at nearly zero velocity. The detection of an obstacle and its identification by the CPU allows for the use of motors of lower power, since quick starts and stops are operations driving motor size and therefore also cost (of the motor and its power consumption), and said operations can be avoided with the present invention.
The safety proportion, Ps, of detection cells identifying the presence of a body at a same time used to trigger the sudden stopping of the shutter (if P≤Ps), or the slowing down of the closing velocity of the shutter (if P>Ps) depends on the number, n, of detection cells, and their position along the leading edge of the shutter. The safety proportion, Ps, is generally comprised between 80% and 100%, preferably between 90% and 100%. If Ps=100%, a body detected by (some of) the detection cells (si) will be considered as the distal transverse edge only in case all the detection cells identify the presence of said body at a same time. In case of a vertical shutter as illustrated in
Although two detection cells (n=2) are theoretically sufficient to carry out the present invention, it is preferred to have a higher number of detection cells distributed along the leading edge of the shutter For example, the array of n detection cells distributed along the leading edge of the shutter preferably comprises at least 3, preferably at least 4, more preferably at least 5 detection cells per metre of leading edge measured along the transverse direction, X2. A higher number of detection cells allows a safer distinction by the CPU between an accidental obstacle and a distal transverse edge. On the other hand, a higher number of detection cells increases the cost of the door. By increasing the angle of the area covered by each detection cell, it is possible to cover the whole area below the door's leading edge. This, however, is at the expenses of a lower accuracy of the definition of the shape of an object detected within the trajectory of the leading edge. A good balance between the requirements and cost of the door must be found in each particular case, a task which is well within the skills of a person of the art.
To further increase the security of the door in case of P≤Ps (i.e., detection of a body considered by the CPU as an accidental obstacle), the CPU may also consider the case wherein all of the n1 detection cells having detected the presence of a body communicate to the CPU that said body is located at a distance, Δx, greater than the predefined safety distance, Δxs, from each of said detection cells, Δx>Δxs, during the moving in the first direction (α) of the shutter at the service closing speed, v1, from the open position (x1,1) towards the closed position (x1,0). If such situation happens, the CPU can thus be programmed to trigger the following operations:
According to a preferred embodiment described above, in case P≤Ps, but none of the detection cells has identified an object at a distance less than Δxs, (Δx>Δxs for all of the n1 detection cells), the CPU considers a predefined precautionary distance, Δxp>Δxs, above which the leading edge continues its run at the service closing speed, v1, and below which the leading edge slows down to a closing speed, v2<v1, as illustrated in
According to another embodiment of the present invention indicated in
The value of the predefined safety distance, Δxs, depends very much on the service closing speed, v1, of the shutter, as it determines the time required for stopping the leading edge before impact. The safety distance can therefore be defined as, Δxs=v1·timp, wherein timp is a safety impact time required for the leading edge to cover the distance, Δxs, at the service closing speed, v1. To be on the safe side, timp is preferably comprised between 0.5 and 3 s, preferably, between 0.8 and 2 s. Service closing speeds, v1, comprised between 0.25 and 1 m/s, preferably between 0.5 and 0.8 m/s, are representative of fast doors. With a service closing speed of 0.75 m/s, and a safety impact time of the order of 1 s, yields a safety distance, Δxs=0.75×1=0.75 m, whilst with a service closing speed of 0.5 m/s, and a safety impact time of the order of 0.8 s, yields a safety distance, Δxs=0.5×0.8=0.4 m.
The detection cells (si) are preferably selected among one or more of the following: ultrasonic sensors, optical sensors, capacitor sensors, radar sensors, radio-frequency sensors, and the like. As illustrated in
In
In
In
In
Unlike the motorized doors of the prior art, a motorized door according to the present invention can distinguish whether an identified body is a distal transverse edge, including a non-permanent raised deck, or an accidental obstacle, and triggers different control procedure of the closing of the shutter accordingly. With a better prediction of the possible stopping of the shutter, a smaller motor can be used. Furthermore, the detection cells can be mounted very easily on the leading edge of existing doors, and coupled to a CPU either by cable or by wave (e.g., Bluetooth). The control of the detection cells can be coupled to the existing CPU originally controlling the movements of the door. Safety and closure efficacy are both enhanced with a motorized door according to the present invention.
Number | Date | Country | Kind |
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1551190 | Sep 2015 | SE | national |
Filing Document | Filing Date | Country | Kind |
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PCT/EP2016/070845 | 9/5/2016 | WO | 00 |
Publishing Document | Publishing Date | Country | Kind |
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WO2017/045954 | 3/23/2017 | WO | A |
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Number | Date | Country | |
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20180245401 A1 | Aug 2018 | US |