Classifications

• • E—FIXED CONSTRUCTIONS
  • E06—DOORS, WINDOWS, SHUTTERS, OR ROLLER BLINDS IN GENERAL; LADDERS
  • E06B—FIXED OR MOVABLE CLOSURES FOR OPENINGS IN BUILDINGS, VEHICLES, FENCES OR LIKE ENCLOSURES IN GENERAL, e.g. DOORS, WINDOWS, BLINDS, GATES
  • E06B9/00—Screening or protective devices for wall or similar openings, with or without operating or securing mechanisms; Closures of similar construction
  • E06B9/56—Operating, guiding or securing devices or arrangements for roll-type closures; Spring drums; Tape drums; Counterweighting arrangements therefor
  • E06B9/80—Safety measures against dropping or unauthorised opening; Braking or immobilising devices; Devices for limiting unrolling
  • E06B9/82—Safety measures against dropping or unauthorised opening; Braking or immobilising devices; Devices for limiting unrolling automatic
• • E—FIXED CONSTRUCTIONS
  • E05—LOCKS; KEYS; WINDOW OR DOOR FITTINGS; SAFES
  • E05F—DEVICES FOR MOVING WINGS INTO OPEN OR CLOSED POSITION; CHECKS FOR WINGS; WING FITTINGS NOT OTHERWISE PROVIDED FOR, CONCERNED WITH THE FUNCTIONING OF THE WING
  • E05F15/00—Power-operated mechanisms for wings
  • E05F15/70—Power-operated mechanisms for wings with automatic actuation
  • E05F15/73—Power-operated mechanisms for wings with automatic actuation responsive to movement or presence of persons or objects
• • E—FIXED CONSTRUCTIONS
  • E06—DOORS, WINDOWS, SHUTTERS, OR ROLLER BLINDS IN GENERAL; LADDERS
  • E06B—FIXED OR MOVABLE CLOSURES FOR OPENINGS IN BUILDINGS, VEHICLES, FENCES OR LIKE ENCLOSURES IN GENERAL, e.g. DOORS, WINDOWS, BLINDS, GATES
  • E06B9/00—Screening or protective devices for wall or similar openings, with or without operating or securing mechanisms; Closures of similar construction
  • E06B9/56—Operating, guiding or securing devices or arrangements for roll-type closures; Spring drums; Tape drums; Counterweighting arrangements therefor
  • E06B9/68—Operating devices or mechanisms, e.g. with electric drive
  • E06B9/70—Operating devices or mechanisms, e.g. with electric drive comprising an electric motor positioned outside the roller
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
  • G01S13/00—Systems using the reflection or reradiation of radio waves, e.g. radar systems; Analogous systems using reflection or reradiation of waves whose nature or wavelength is irrelevant or unspecified
  • G01S13/88—Radar or analogous systems specially adapted for specific applications
• • E—FIXED CONSTRUCTIONS
  • E05—LOCKS; KEYS; WINDOW OR DOOR FITTINGS; SAFES
  • E05Y—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES E05D AND E05F, RELATING TO CONSTRUCTION ELEMENTS, ELECTRIC CONTROL, POWER SUPPLY, POWER SIGNAL OR TRANSMISSION, USER INTERFACES, MOUNTING OR COUPLING, DETAILS, ACCESSORIES, AUXILIARY OPERATIONS NOT OTHERWISE PROVIDED FOR, APPLICATION THEREOF
  • E05Y2400/00—Electronic control; Electrical power; Power supply; Power or signal transmission; User interfaces
  • E05Y2400/10—Electronic control
  • E05Y2400/32—Position control, detection or monitoring
  • E05Y2400/35—Position control, detection or monitoring related to specific positions
  • E05Y2400/356—Intermediate positions
• • E—FIXED CONSTRUCTIONS
  • E05—LOCKS; KEYS; WINDOW OR DOOR FITTINGS; SAFES
  • E05Y—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES E05D AND E05F, RELATING TO CONSTRUCTION ELEMENTS, ELECTRIC CONTROL, POWER SUPPLY, POWER SIGNAL OR TRANSMISSION, USER INTERFACES, MOUNTING OR COUPLING, DETAILS, ACCESSORIES, AUXILIARY OPERATIONS NOT OTHERWISE PROVIDED FOR, APPLICATION THEREOF
  • E05Y2900/00—Application of doors, windows, wings or fittings thereof
• • E—FIXED CONSTRUCTIONS
  • E05—LOCKS; KEYS; WINDOW OR DOOR FITTINGS; SAFES
  • E05Y—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES E05D AND E05F, RELATING TO CONSTRUCTION ELEMENTS, ELECTRIC CONTROL, POWER SUPPLY, POWER SIGNAL OR TRANSMISSION, USER INTERFACES, MOUNTING OR COUPLING, DETAILS, ACCESSORIES, AUXILIARY OPERATIONS NOT OTHERWISE PROVIDED FOR, APPLICATION THEREOF
  • E05Y2900/00—Application of doors, windows, wings or fittings thereof
  • E05Y2900/10—Application of doors, windows, wings or fittings thereof for buildings or parts thereof
  • E05Y2900/106—Application of doors, windows, wings or fittings thereof for buildings or parts thereof for garages
• • E—FIXED CONSTRUCTIONS
  • E06—DOORS, WINDOWS, SHUTTERS, OR ROLLER BLINDS IN GENERAL; LADDERS
  • E06B—FIXED OR MOVABLE CLOSURES FOR OPENINGS IN BUILDINGS, VEHICLES, FENCES OR LIKE ENCLOSURES IN GENERAL, e.g. DOORS, WINDOWS, BLINDS, GATES
  • E06B9/00—Screening or protective devices for wall or similar openings, with or without operating or securing mechanisms; Closures of similar construction
  • E06B9/56—Operating, guiding or securing devices or arrangements for roll-type closures; Spring drums; Tape drums; Counterweighting arrangements therefor
  • E06B9/68—Operating devices or mechanisms, e.g. with electric drive
  • E06B2009/6809—Control
  • E06B2009/6818—Control using sensors
• • E—FIXED CONSTRUCTIONS
  • E06—DOORS, WINDOWS, SHUTTERS, OR ROLLER BLINDS IN GENERAL; LADDERS
  • E06B—FIXED OR MOVABLE CLOSURES FOR OPENINGS IN BUILDINGS, VEHICLES, FENCES OR LIKE ENCLOSURES IN GENERAL, e.g. DOORS, WINDOWS, BLINDS, GATES
  • E06B9/00—Screening or protective devices for wall or similar openings, with or without operating or securing mechanisms; Closures of similar construction
  • E06B9/56—Operating, guiding or securing devices or arrangements for roll-type closures; Spring drums; Tape drums; Counterweighting arrangements therefor
  • E06B9/68—Operating devices or mechanisms, e.g. with electric drive
  • E06B2009/6809—Control
  • E06B2009/6818—Control using sensors
  • E06B2009/6836—Control using sensors sensing obstacle
• • E—FIXED CONSTRUCTIONS
  • E06—DOORS, WINDOWS, SHUTTERS, OR ROLLER BLINDS IN GENERAL; LADDERS
  • E06B—FIXED OR MOVABLE CLOSURES FOR OPENINGS IN BUILDINGS, VEHICLES, FENCES OR LIKE ENCLOSURES IN GENERAL, e.g. DOORS, WINDOWS, BLINDS, GATES
  • E06B9/00—Screening or protective devices for wall or similar openings, with or without operating or securing mechanisms; Closures of similar construction
  • E06B9/56—Operating, guiding or securing devices or arrangements for roll-type closures; Spring drums; Tape drums; Counterweighting arrangements therefor
  • E06B9/68—Operating devices or mechanisms, e.g. with electric drive
  • E06B2009/6809—Control
  • E06B2009/6818—Control using sensors
  • E06B2009/6845—Control using sensors sensing position

Definitions

• the present invention generally relates to a device for automatically controlling the operation of a door of the type having a door leaf and, connected thereto, a drive means, said device comprising a means adapted to detect the presence of an object approaching the door to pass therethrough, and in response actuate the drive means which then opens the door. More specifically, and in a • first aspect, the invention concerns such a device which is designed to control the degree of opening of a verti ⁇ cally adjustable door leaf as a function of the height of the detected object. In a second aspect, the invention concerns such a device which is designed to control the degree of opening of an e.g. laterally movable door leaf.
• 'door' are meant all types of doors, gates and the like which have some sort of movable shutting member for opening and closing the door.
• the invention may for instance be applied to roll-up doors, roof sliding doors and folding doors.
• the prior art encompasses control devices designed for doors with a vertically adjustable door leaf and ope ⁇ rating with a plurality of predetermined and fixed verti- cally distributed limit positions or levels at which the door leaf can be selectively stopped during its opening movement.
• the reason for providing several separate ver ⁇ tical limit positions for the door instead of opening the door completely each time an object is detected, is that one may thus avoid the energy loss, wear and waiting time resulting from opening the door more than required. If e.g. a person is to pass through a six-metre door, it is not necessary to open the door as far as when e.g. a high truck is to pass through.
• prior-art control devices are equipped either with manually operated selectors for choosing between the different, separate limit positions, or a special height- selective transducer for each limit position.
• the latter alternative may be designed (i) in such a manner that a first transducer in the form of a pull grip being pulled by people walking towards the door, in order to open the door to a lowest predetermined level Nl, (ii) in such a manner that a second transducer in the form of a photocell located at a given medium level in front of the door is affected by objects of sufficient height to block the pho ⁇ tocell, in order to open the door to a predetermined intermediate level N2, and (iii) in such a manner that a third transducer in the form of a radar with a height- selective sensitivity range responds to even higher objects in order to open the door to a highest predeter ⁇ mined level N3.
• these predetermined and fixed door-leaf limit positions are obtained either by fixed limit switches, or the like, which are fixedly mounted on the side stands of the door to be actuated by the door leaf, or by a combination of microswitches and cams operatively connected to the drive means.
• the electric output signals from the height-selective transducers such as a pull grip, a photocell and a radar, are predetermined and constant and do not contain in themselves any information whatsoever on the height of the object. The signals only tell whether or not the transducer is affected.
• the above control devices are impaired by a number of drawbacks. 1. They require the use of a separate transducer and a separate limit switch or microswitch per limit position or level, which means that the construction not only becomes expensive, complicated and susceptible to errors, but also that it will require a great deal of maintenance. 2. The distance between the vertically distributed limit positions is restricted by the space available for the limit switches on the door stand or the combination of microswitches and cams associated with the drive means. In other words, the resolution between the fixed limit posi- tions is restricted, and the degree of opening of the door therefore cannot be exactly adjusted to the height of the objects that are to pass through.
• control unit such as an electronic data-processing unit (CPU), having one input for each height-selective transducer, which further increases the cost, both for manufacturing the CPU and for the running of wires and the installation in general.
• CPU electronic data-processing unit
• One object of the present invention is to obviate the above drawbacks (1-4) impairing the prior art.
• a first aspect of the inven ⁇ tion provides a door-control device which is of the type stated in the introduction to this specification and which is designed for a door with a vertically adjustable door leaf and which is characterised by a first sensor means adapted to detect the height of the object when this approaches the door, and to emit a first signal containing information on the detected height of the object; a second sensor means adapted to respond to the opening movement of the door leaf by continuously emitting during said move- ment a second signal containing information on the current degree of opening of the door leaf; and a signal-process ⁇ ing means adapted to receive the first output signal and the second output signal in order to compare the informa ⁇ tion on the detected height of the object with the infor- ma ion on the current degree of opening of the door leaf and, in response to the result of this comparison, cause the drive means to substantially steplessly guide the door leaf towards a stop position in which the degree of open ⁇ ing of the door leaf corresponds to the detected height of the object.
• the device according to the invention is primarily distin ⁇ guished by enabling stepless control of the door leaf, when being opened, to a stop position corresponding to the height of the object.
• the invention there are thus no given, fixed limit positions or levels for the door leaf (optionally excepting the positions in which the door is completely open or completely closed), but a new stop position for the door is established by the signal- processing means each time an object is to pass through the door.
• the degree of opening of the door can be steplessly adjusted to the height of the object each time the door is opened, the above inconveniences of unneces ⁇ sary loss of energy, wear and waiting time can be com- pletely eliminated without the use of a great number of separate transducers and separate door-position sensing switches or microswitches and a control unit with many inputs.
• the degree of opening of the door leaf in the stop position determined by the sig ⁇ nal-processing means corresponds to the detected height of the object, as indicated above.
• the expression 'corre- sponds to' is to be taken in a broad sense and includes the following cases in particular:
• the stop position is so determined by the signal- processing means that the door leaf is stopped in a position allowing the object to just about pass under the lower edge of the door leaf.
• the stop position is so determined by the signal- processing means that the door leaf is stopped in a position allowing the object to pass under the lower edge of the door leaf by a predetermined safety mar ⁇ gin.
• the stop position is continuously updated by the signal-processing means from the first detection of the presence of the object, so that the most recently determined stop position at all times corresponds to the maximum height detected by the first sensor means in the object, once the presence thereof has been detected.
• This alternative which thus continuously measures the height and which is suitably combined with the safety margin of alternative (b), might be said to constitute a preferred embodiment eliminat ⁇ ing every risk of the door being run into should the object have a varying height in its direction of travel.
• the first sensor means includes a trans ⁇ mitter means for transmitting electromagnetic or acoustic detection signals towards the object, as well as a receiv ⁇ er means for receiving the detection signals.
• the first sensor means is adapted to be mounted in a position above the path of motion of the object approaching the door, the height information con ⁇ tained in the first signal corresponding to the transit time of the detection signals from the transmission to the reception after reflection against the object. This 'echo- based' method has the advantage of not involving any risk of the sensor means being run into or otherwise damaged.
• the transmitter means is adapted to be mounted on one side of the path of motion of the object moving towards the door;
• the receiver means includes a plurality of vertically distributed, separate receivers to be mounted on the opposite side of the path of motion of the object to receive the detection signals from the transmitter means;
• the first sensor means further includes a converter means connected to the sepa ⁇ rate receivers and adapted to generate the first signal, the height information contained in the first signal being based on the number of separate receivers blocked by the object approaching the door.
• the first sensor means may have an extended sensiti ⁇ vity range transversely of the direction of motion of the object moving towards the door, so as to detect the maxi ⁇ mum height of the object if this possesses a varying height transversely of its direction of motion towards the door.
• the means for detecting the presence of the object may also, in accordance with the prior art, do so in response to the object affecting the height-detecting first sensor means, thereby altering the state of the first signal.
• the second sensor means serving to continuously retrieve information on the current degree of opening or vertical position of the door leaf during the opening pro ⁇ cedure, preferably includes a pulse generator which is operatively connected to the drive means (or to a trans ⁇ mission mechanism connected to the drive means or to e.g. the winding roller of the door leaf of a roll-up door).
• the pulse generator continuously emits a sequence of pulses which form the second signal and whose relative time intervals correspond to the opening rate of the door leaf.
• the signal-processing means can then integrate the pulses so as to continuously determine the current degree of opening during the opening movement of the door leaf.
• Such a pulse generator thus provides substantially analog information on the current degree of opening of the door leaf.
• the signal in itself is digital since it is composed of discrete pulses, the time intervals therebetween can be made so short that the information, in practice, can be regarded as analog. Anyhow, the reso ⁇ lution enabled by such a pulse generator is considerably higher than that which can be obtained by using the known limit switches or the known combination of microswitches and cams.
• a potentiometer optionally a multiturn potentio ⁇ meter, which is operatively connected to the drive means or to members driven thereby, such as the winding roller of a roll-up door.
• the door-con ⁇ trol device has a third sensor means for detecting the speed at which the object approaches the door.
• a signal containing information on the speed is fed to the signal- processing means which in response can determine how long it will take for the object to reach the door, and the rate of opening of the door leaf can thus be adjusted to different speeds of the objects approaching.
• the signal-processing means can be designed to delay the actuation of the drive means, so that opening of the door will not begin until it is absolutely necessary. This makes it possible to avoid e.g. unnecessary energy losses, should there be a desired temperature difference between the spaces on both sides of the door.
• the above-mentioned detection of the speed of objects approaching the door is especially preferred in the case of a roll-up door being arranged transversely of a con ⁇ veyor, e.g. a conveying belt, to let through objects transported on the belt.
• a con ⁇ veyor e.g. a conveying belt
• feed-back servo control of the degree of open ⁇ ing of the door can be achieved that the lower edge of the door continuously and by a certain safety margin accom ⁇ panies that part of the object which at the moment is situated in the door opening.
• the control device according to the first aspect of the invention is designed to control the degree of opening of a vertically adjustable door leaf.
• the invention is not, however, restricted to vertically movable door leaves but is also applicable to e.g. horizontally movable door leaves of either single or double design, which however requires a certain modification taking into account the fact the object may approach the door in varying posi ⁇ tions.
• the invention there- fore provides a device for automatically controlling the operation of a door of the type having a door leaf designed to open and close a door opening and having a closing edge arranged to move in the plane of the door opening, and, connected thereto, a drive means, said device comprising a means adapted to detect the presence of an object moving towards the door to pass therethrough, and in response actuate the drive means which then opens the door, said device being characterised by a first sensor means which is adapted to detect, when the object approaches the door and passes a detection plane parallel to the plane of the door opening, the position in said detection plane of the point of the object whose perpen ⁇ dicular projection on the plane of the door opening is at the longest distance from the closing edge of the door leaf in closed position, said first sensor means being adapted to emit a first signal containing information on said longest distance; a second sensor means adapted to respond to the opening movement of the door leaf by conti ⁇ nuously emitting during said movement a second signal con ⁇ taining information
• the first sensor means may include separate receiver means which are suit- ably positioned adjacent to the path of motion of the object moving towards the door, e.g. so as to extend parallel to the door above the path of motion.
• the stop position can also be continuously updated, substantially in the manner described above in connection with the first aspect of the invention.
• the means for detecting the presence of the object can do so in response to the object affecting the first sensor means.
• the stop position can also be such that the object can pass through the door and under the door leaf by a given margin.
• a pulse generator of the above type may also be used for the second sensor means.
• Fig. 1 schematically and in block form illustrates an embodiment of the invention applied to a roll-up door with a vertically adjustable door leaf
• Fig. 2 schematically illustrates a sensor variant for height detection
• FIG. 3 schematically and in block form illustrates an embodiment of the invention that is applied to a conveying belt and is equipped with speed-detecting means
• Fig. 4 schematically illustrates a second aspect of the invention.
• Fig. 1 schematically illustrates a roll-up door 10 which includes a winding roller 12 extending horizontally above the door opening, a flexible door leaf 14 which is laterally controlled by side stands (not shown) of the door and which is designed to be wound round and unwound from the roller 12, and a drive means in the form of an electric motor 16 for driv ⁇ ing the roller 12 via a transmission mechanism 18.
• the door 10 is partly open, the current degree of opening of the door leaf relative to a floor surface 20 or the like being designated h.
• the control device includes a first sensor means 24, here in the form of a transmitter 26 and a receiver 28 for transmitting and receiving, respectively, electromagnetic or acoustic detection signals 30 for detection of the height H of the object 22.
• the transmitter 26 and the receiver 28 are both mounted in the ceiling or on a stand above the path of motion of the object 22.
• a corresponding sensor means 24 can be arranged also to the right of the door 10 in Fig. 1.
• the first sensor means 24 emits a first signal SI containing information on the height H of the vehicle, this height H being based on the total transit time from transmission to reception of the signals 30 reflected against the object 22.
• the signal SI is fed to a signal- processing means 32.
• the device according to the invention further in ⁇ cludes a second sensor means 34, here in the form of a pulse generator, which is operatively connected to the winding roller 12.
• the pulse generator 34 emits a second signal S2 consisting of a sequence of pulses whose rela ⁇ tive time intervals are controlled by the rotational speed of the roller 12, i.e. the opening rate of the door leaf 14.
• the signal S2 containing these pulses is fed also to the signal-processing means 32 where the signal S2 is integrated for continuous determination of the cur ⁇ rent degree of opening h of the door leaf 14.
• the signal-processing means 32 causes the motor 16 to start opening the door, as indicated by a line 36 in Fig. 1.
• the height H of the object 22 and the degree of opening h of the door leaf 14 are continuously determined.
• the H and h values are compared in the signal-processing means 32 which, on the basis of the result of this compa ⁇ rison, continuously computes a stop position for the door leaf corresponding to H.
• the object 22 in Fig. 1 has a varying height in its direction of motion P, and since the height of the object 22 is continuously detected and the above comparison is continuously performed, the updated final stop position will correspond to the maximum height H of the object 22.
• Fig. 2 illustrates a variant of the height-detecting first sensor means 24.
• the transmitter 26 is arranged on one side of the path of motion of the object 22 moving towards the door and includes a plurality of separate, vertically distributed transmitter units 26a-26f for transmitting a corresponding number of detection signals 30 transversely of this path.
• the receiver 28 is arranged on the other side of the path and includes a corresponding number of separate, vertically distributed receiver units 28a-28f.
• the number of blocked receiver units 28a-28f is a function of the height H of the object 22.
• Output signals from each receiver unit are fed to a converter 40 which converts the information from the receiver units to the first signal SI which contains information on the height H of the object 22.
• Fig. 3 schematically illustrates a roll-up door 10 which is arranged above a conveyor 42 transporting objects 22 towards the door.
• the opening and closing movement of the door 10 is controlled by a device according to the invention of the above type, i.e. the degree of opening of the door leaf 14 is steplessly adjusted to the detecte height of the object 22.
• the arrangement shown in Fig. 3 further includes a means 44 which is operatively connecte to the conveyor 42 and is adapted to detect the speed of the conveyor 42 (i.e. the speed of the objects 22) travelling towards the door 10. A corresponding signal is fed to the signal-processing means 32.
• the signal-processing means provides such servo control o the door 10 that the door leaf 14 at all times adjusts itself to the upper side of the object 22 currently locat- ed in the door opening.
• this technique can be used for feeding discrete objects, as illustrated in Fig. 3, as well as continuous objects.
• FIG. 4 schematically and in block form illustrates another embodiment of the invention, which is applied to a roll-up door with a laterally movable door leaf.
• Figs 1-3 and Fig. 4 have like refe ⁇ rence numbers.
• the object 22 is transported on a conveying belt 50 in the direction indicated by the arrow P towards the roll-up door whose door leaf 14 is closed and extends above the conveyor 50 in Fig. 4.
• the closing edge of the door leaf 14 is designated 14'
• a plane coinciding with the door opening is designated 52.
• detection plane 54 which is parallel to the plane 52 of the door opening. At that point, detection is made of the position in the detection plane of the point T of the object 22 whose perpendicular projection T' on the door-opening plane 52 is at the longest distance D from the closing edge 14' of the door leaf 14 when closed.
• the position of the point T can be detected in many different ways, e.g. with the aid of electromagnetic or acoustic detection signals emitted from the side of the conveyor 50, in which case the transit time is measured after reflection.
• a sensor extend ⁇ ing transversely of the conveyor 50 can be provided above the object, or use can be made of a CCD camera.
• the signal emitted by the first sensor means thus contains information on the distance D, which can be compared with the height H in the embodiment illustrated in Figs 1-3. As described above, the door leaf 14 is then guided towards a stop position corresponding to the distance D.
• the object 22 in Fig. 4 has a point T" which has not yet reached the detection plane 54. It will be appreciated that the object 22 preferably is sensed continuously so that the determined stop position of the door leaf 14 is updated, as described above in connection with Figs 1-3.
• the object 22 is moving at an angle to the door-opening plane 52.
• the object 22 may, for instance, be a truck approaching at an oblique angle to the door-opening plane 52. If so, several successive detection planes are conve ⁇ niently arranged to update the determined stop position of the door leaf 14.

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• Engineering & Computer Science (AREA)
• Structural Engineering (AREA)
• Radar, Positioning & Navigation (AREA)
• Remote Sensing (AREA)
• Physics & Mathematics (AREA)
• Architecture (AREA)
• Civil Engineering (AREA)
• Electromagnetism (AREA)
• Computer Networks & Wireless Communication (AREA)
• General Physics & Mathematics (AREA)
• Power-Operated Mechanisms For Wings (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=20381309

Family Applications (1)

Country Status (2)

Cited By (4)

Citations (2)

• 1990
  • 1990-12-20 SE SE9004139A patent/SE467846B/sv not_active IP Right Cessation
• 1991
  • 1991-12-20 WO PCT/SE1991/000902 patent/WO1992011544A1/en active Application Filing

Patent Citations (2)

Non-Patent Citations (1)

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