Lifting door with a slatted armor having articulated slats

RELATED APPLICATIONS
This invention is a continuation of PCT Application No. PCT/EP91/00887, filed May 13, 1991.
Background of the Invention
The invention relates to a lifting door with a slatted armor which is movable vertically upwards from a closed position into an open position relative to a door aperture.
In DE-A-3 244 743, there is described a rolling wall for refrigerating and insulating containers consisting of a heat insulating material and being provided with heat insulated compound profiles made of light metal. The compound profiles are equipped at their adjacent longitudinal edges with respective undercut grooves. For connecting faceing slats, a connecting strap produced from rubber or from a correspondingly elastic material is provided which interlockingly engages the undercut grooves of the compound profiles.
A known example of a lifting door is a rolling door which functions as a vertically opening closure of a walk-through or drive-through door aperture. Such lifting door conventionally consists essentially of a rolling armor, having mutually pivotally connected slats which are guided into the closed position at the two side edges of the door aperture by means of vertical guide rails, a winding shaft to which the rolling armor is fastened for moving an electromotive drive, and a catch device which prevents the rolling armor from crashing down in the event of a failure of the drive.
The rolling armor functioning as the part of a rolling closure which closes off and protects the door aperture consists of slats, generally profiled parts, for example extruded aluminum materials, connected to one another in an articulated manner. The height of the individual slats is, generally approximately 80 to 120 mm. These profiled parts are usually provided as push-in profiles which, on account of their shape, are connected to one another in an articulated manner without further connecting members, to form the rolling armor. In a typical aluminum extruded profile, the joint is designed, for example, as a cup and web, so that, with the profiles pushed into one another, the joint thus formed can absorb and withstand the forces occurring when the rolling armor is being wound up. The connection of the slats which is shaped to form a joint has, generally, a large play. Moreover, with the profiles pushed into one another, dirt and water are prevented from settling in the joints and sufficient sealing against wind is provided.
The roll layers on the winding shaft are formed by the interconnected profiles which have a specific profile height. Each profile is laid onto the most projecting edge of a profile of the layer located underneath it. The direction which a profile assumes within its roll layer in the cross-section of the roll depends on the bearing point of the profile. By its randomly assumed position, it also determines, in turn, the arrangement of the next profile connected to it. This results, with the roll wound up, in an irregular layered arrangement of the individual profiles of the rolling door. It follows from this, that, for example, only a single edge of a single profile of the rolling door supports the entire load of the armor part still hanging freely, as a consequence of which considerable edge pressures can occur.
As a safeguard against lateral displacement, head pieces or end pieces, which run in corresponding vertical guide rails each having, as a generally, U-shaped cross-section, are, fastened laterally to the profiles of the typically rolling door. These vertical guides are-widened in a funnel-shaped manner at their upper entrance, so that the rolling armor, when being unrolled, can run perfectly into the vertical guide, without the risk that it will become caught.
The rolling armor is fastened by means of its initial profile to the winding shaft in such a way that, with the door closed, the fastening is located on the side of the shaft facing away from the armor. Thus the armor or the end plates lengthens the armor loop round the shaft by at least 180.degree..
This ensures that the armor is held largely by frictional forces, and therefore the full dead weight of the armor does not act upon the suspensions. The door is closed when the tail profile rests sealingly on the lower edge of the aperture, i.e., generally on the ground. Moreover, the rolling armor should not collapse. The entire armor, with the exception of the tail profile, thus remains hanging as a load on the shaft or shaft axle. The rolling door thereby differs fundamentally from the roller blind which is usually provided as an additional closure of an aperture.
In the open position of the rolling door, the rolling armor rolled up onto the winding shaft is located in the lintel region-of the door aperture. The drive usually lies protected behind the lintel and therefore cannot be damaged by vehicles when they drive through the door aperture. An electric motor is typically provided, as a drive, and furthermore a hand-operated drive is available for temporary operation.
An electric drive is employed and, the rolling-door shaft is driven at a constant rotational speed, i.e., at a uniform angular speed. The rolling armor fastened to the shaft is thereby raised and wound up onto the shaft. A critical factor in the lifting speed is, the particular effective winding radius which is increased continuously during the winding, since the lower parts of the rolling armor are laid onto the already wound upper parts. Since the lifting speed changes in direct proportion to the roll radius, a rolling door first runs upwards slowly, becoming more and more rapid in the upward direction. In a closer consideration of the kinematic conditions, and allowing for the thickness and height of the profiles, the rolling-door roll must be viewed as a polygon. During the winding, the profiles are first laid onto the round winding shaft. The straight profiles form a polygon thereon. At the same time, the corners of the polygon are further away from the center point of the shaft than the centers of a side of the polygon. When the shaft of the rolling door is rotated at a constant angular speed, the rolling armor is pulled up with a lever arm corresponding to the length to the corner point of the polygon and at the lifting speed corresponding to the lever-arm length and in the next moment with a lever arm corresponding to the length to a side of the polygon and at the lifting speed corresponding to this. The lifting speed is directly proportional to the particular effective lever arm occurring discontinuously and irregularly and is therefore characterized, during the winding up of the rolling armor, by correspondingly pronounced and sudden fluctuations. This is accompanied by mass accelerations and decelerations of fluctuating amounts of the still unwound mass of the rolling armor. These mass accelerations also enter the gear of the drive motor, which gear has to be designed for an appropriate degree of non-uniformity, since breakdowns can otherwise occur. These accelerations are, smaller, the thicker the rolling-door roll becomes, i.e., the more the polygon approximates a circle. However, since the highest mass accelerations and decelerations occur when the rolling armor is closer to its closed position, these forces are therefore still mutually augmented as a result of the appreciable dead weight of the rolling armor.
The accelerations and decelerations of the masses of the unwound rolling armor cause vibrations. These vibrations also act by way of the winding shaft on the building, and therefore the static calculation of the building must make sure that the natural vibration frequency remains outside the rolling-door frequencies. Otherwise, the lifting speed of the rolling door has to be drastically reduced. At a uniform angular speed of the rolling-door shaft, with an increased thickness of the rolling-door roll the frequency of the vibrations will increase and their amplitude decrease. This means, conversely, that the generation of sound during the actuation of the rolling door becomes greater, the further the rolling armor comes down.
In addition to the abovementioned irregularities in the lever-arm ratios during the winding up of the profiles in the form of polygonal courses, in the hitherto known rolling doors, there is a further irregularity which also leads to extremely problematic kinematic conditions. Since the driven shaft of a rolling door cannot exert any pressure forces on the rolling armor, it is necessary to ensure that, in the raised state, the falling weight of the freely hanging part of the rolling armor, together with the lower rail, is greater than the friction of rest. Only thus is the armor automatically set in motion, as a result of its own gravitational force, when the shaft is driven in the downward direction. The least friction for the armor is provided when it runs in the raised state vertically into the guides. This type of mounting is called "normal stance". In proportion as the rolling armor runs down, the roll diamater decreases. The armor then runs increasingly more obliquely into the entrances of the guides. When the rolling armor has run down completely, but, as is customary with rolling doors, still hangs with a pull on the shaft, the entire load of the rolling armor in some circumstances hangs only on a single profile of the profiles still located on the shaft. If the vertical cross-section of a rolling door is considered, it will be seen that the pull of the entire dead weight of the armor is not in the door plane, but in the rectilinear connection between the bottom piece and the effective roll radius. The rolling armor will therefore experience deformation in the middle between the guides, in order to come as close as possible to the path of the tensile stress. However, the profile ends are held by the guides and cannot follow the line of tensile stress. Whereas the tensile stress resulting from the dead weight of the rolling armor pulls the armor on the upper part out of the door plane in the direction of the shaft, the guides bend the profile ends towards the door plane again. The individual profiles are thereby subject not only to bending stress, but also to torsional stress. The highest bending and torsional moments occur at the entrance.
In order to reduce the sealing problems involved in the "normal-stance" type of mounting, it was proposed to limit the bending by attaching a pressure shaft. However, this entails a more unsteady and noisier running of the rolling door (see Horst Gunter Steuff, "Das Rolltor", ["The Rolling Door"], Dusseldorf, Werner Verlag GmbH, 1987, page 93).
The above-described unfavorable kinematics of the rolling door which has been known (and hitherto scarcely changed) in its basic features for more than one hundred years is to be seen as the main reason for the generation of a large amount of noise during running and, in the final analysis, also for the insufficient high-speed property of the rolling door. The running noises originating essentially from the profile joints occur mainly during the upward travel of the rolling door and then also to an especially pronounced extent in the lower third of the door aperture, in so far as the rolling door has a "normal stance". The noises arise in the vicinity of the leadin, where the profiles bend, are subjected to high pulls and are rotated in the joints.
Although the hitherto known rolling doors, on account of the non-positive and positive connections of its slats, was for a long time considered to be the most cost-effective solution in terms of sealing against wind pressure and safety against unauthorized opening, the poor high-speed properties of the conventional rolling door were recognized at an early stage as being disadvantageous when it was used as an industrial door. The running speeds of a conventional rolling door are approximately 0.25 to 0.35 m/s.
In the industrial sector, high-speed rolling doors having a full-surface door leaf made of flexible material, which can be wound onto a winding shaft or winding drum, have also proved successful as an additional aperture closure. Moreover, rolling doors of this type, if a suitable flexible material is chosen, have the advantage of visual transparency. Macrolon foils or soft PVC foils, for instance, are in widespread use. However, this advantage over opaque material disappears in time, since the visual transparency is impaired as a result of the penetration of dust and the like during the winding up of the foil, and the associated scratching of the surface.
In view of the limited amount of space available above the lintel region and the large core diameter of the shaft, conventional in foil-type rolling doors, the foils in this type of rolling door have to be as thin as possible, since the overall winding diameter otherwise becomes too large. Furthermore, the provision of thinner foils at the same time allows the door leaf to run at higher speed on account of the easier windability. The small thickness of the foils and accordingly the low dead weight of the door leaf nevertheless lead to a reduced wind-resisting strength. It was proposed, as a remedy for this, to provide additional weight in the form of a closing profile, arranged on the lower edge of the door leaf, or spring-loaded tensioning belts which run over deflecting rollers mounted on the ground.
The greatest disadvantage of the foil-type rolling doors therefore arises from the behavior of the door leaf under wind pressure, which approximates more closely to the behavior of a sail than to the behavior of a plate. Since the door leaf is supported only on the winding shaft, under wind load the door leaf becomes considerably distended and bulged and is consequently also lifted. Rolling doors of this type are therefore to be considered only as an additional closure for a door aperture also in view of deficient safety against unauthorized opening.
Furthermore, so-called sectional doors, e.g., U.S. Pat. No. 3,891,021, which are likewise used for large door apertures, are known. A conventional sectional door consists essentially of an armor having comparatively high sections which can be circulated out of the vertical closed position into an upper horizontal position underneath the ceiling by means of a cable drive.
The comparatively large height of the individual sections which is used in sectional doors results, on account of the reduced number of connecting elements for the sections, such as hinges or the like, and also the reduction in the number of end faces to be sealed off, in a mechanically altogether more compact design having correspondingly good strength against wind forces and safety against unauthorized opening. Furthermore, the large height of the individual sections makes it possible to provide transparent portions in the form of glass or plastic windows.
The compact design of sectional doors makes it possible, to provide light-weight doors composed of aluminum sections which are filled, for example, with a plastic material for heat and sound insulation, in order to make it possible to open and close garage doors even with relatively large door widths solely by manual actuation without an additional electric-motor drive.
As a rule, the individual sections lie on one another in alignment in the closing position, so that the entire end face of a particular section is available for the sealing. The sectional door thus appears almost exactly as a closed door with a continuous outer surface, without intermediate gaps. Further improved sealing is brought about, for example, by rubber inserts which are compressed, in the closed position, by the sections lying above one another. Alternatively, the sections have a bulge which extends on one end face over the entire door width and which engages into a corresponding depression of an adjacent section during the pivoting of the sections into the same plane like a tongue-and-groove joint, thereby further improving the mechanical strength of the door leaf against wind pressure, even where large door widths are concerned.
On the inside of the door, the sections are connected by means of a plurality of individual hinges which are mounted over the entire width of the door at particular intervals in such a number that sufficiently high strength and support is achieved. The hinges mounted on the lateral edge of the sections are typically designed at the same time as a holder for a roller which can run in a guide rail of U-shape cross-section on the edge region of the sectional door. Since the individual hinges are mounted on the sections in such a way that the sections can be folded away towards the inside, problems arise here in as much as the parts of the hinges mounted on the inside of the door and projecting are visually displeasing and cause danger of injury. A further danger of injury on sectional doors is caused during the angling of the sections, by the open gaps occurring thereby, or during the folding back of the sections and the closing of the gaps.
A further disadvantage of sectional doors having relatively high sections emerges in connection with the arcuate guide part above the lintel region, where the individual sections are articulated from the vertical position into the horizontal position. This movement naturally leads to sudden tilting accelerations and correspondingly, in response to rapid actuation, to considerable force effects on the individual sections. Acceleration and deceleration forces occur as a result of the different radial distances of the guide rollers from the actual location of the mass of the section in the region of the upper curved path, the generally non-uniform force pattern resulting from the plane design of the slats of finite height, which are present in the curved path in the manner of a polygon, whereby sectional doors can be operated only at relatively low running speeds, without the risk that a relatively large amount of noise will be generated.
The transmitted transverse forces are also absorbed, by way of the plurality of individual hinges, by the body of the sections and therefore subject these body section to load. The forces introduced into the edge hinges and correspondingly into the guide rail when the sections are being moved are essentially dependent on the speed of opening and closing of the sectional door. Because the construction is not, in principle, designed for high speeds, limits are placed on the use of sectional doors as industrial doors having a high-speed capability.
In sectional doors, a cable device with hauling cables and carrying cables and cable pulleys arranged on a drive shaft are, conventionally provided as a drive system. During the upward travel of the door, the carrying cables are wound onto the cable pulleys, whilst the hauling cables are simultaneously unwound from the cable pulley. During the downward travel of the door, the hauling cables are wound up and thus pull the door down, whilst the carrying cables, without becoming slack, are simultaneously unwound from the cable pulleys. The carrying cables are thereby constantly subjected to tensile stress and cannot run down from the cable pulleys. The drive shaft is driven via-an electric motor which, for example, is arranged directly underneath the ceiling.
As is known, to balance the weight of the door leaf, there are torsion springs which are arranged coaxially relative to the continuous drive shaft. In the closed position of the door, the torsion springs are fully tensioned and are correspondingly relaxed during the upward movement of the door leaf. These torsion springs are subject to increased wear and their lifetime is therefore considerably limited. Particularly in the event of a frequent and sudden reversal of direction of the cycle of movement of the sectional door, the torsion springs undergo considerable dynamic stress peaks as a result of the jolting movements. The failure of the torsion spring means that the maintenance and exchange work accompanying this in the sectional doors is time-consuming and laborious.
Because the drive shaft together with the torsion springs is arranged above the arc and the electric motor is arranged in the vicinity of the drive shaft, in conventional sectional doors it is necessary to allow for a considerable space requirement above the lintel which, without special constructive measures, for example, the provision of a double horizontal guide underneath the ceiling or the shifting of the drive shaft together with the torsion springs to the outermost end of the running rails, does not fall below a value of typically 400 mm. Added to this is the space requirement in terms of depth which is excessively high in sectional doors and which corresponds essentially to the clear height of the door aperture. Since the free space available, typically in depth, i.e., the dimension between the rear edge of the lintel and the nearest obstacle in the depth of the room, for example, joist, wall, ventilation pipe, fan or the like, will be meager, and in many instances, the installation of the known sectional door may be impracticable.
BRIEF DESCRIPTION OF THE PRESENT INVENTION
Accordingly, it is an object of the present invention to provide a lifting door which allows high-speed running, eliminating or minimizing the generation of noise during the opening and closing of the door, and which, in the closed state, offers sufficient sealing against wind and weather and safety against unauthorized opening.
In a lifting door according to the invention, the slatted armor has hinge straps of a length which corresponds to the height of the door aperture. The hinge straps are supported and guided in the guide tracks. These hinge straps form the supporting structure of the slatted armor, since all the forces occurring during the movement of the lifting door are absorbed by the hinge straps and are distributed essentially over the entire length of each hinge strap. This makes a substantially faster running of the lifting door possible, without the course of movement becoming irregular and unsteady. The individual slats are attached at a distance from one another to the hinge members of the hinge straps, in such a way that respective adjacent slats can be angled or articulated relative to one another by means of the hinge strap. An interspace is formed in the clearance between adjacent slats, into which hinge pins of the hinged straps are disposed. Because the pivot axis of each hinge is provided within this space between the slats, openings between the adjacent slats and also the tilting accelerations when the slats move into the upper guide tracks are minimized, with correspondingly lower acceleration forces during articulation and with the consequently possible higher running speeds of the lifting door. Additionally, projecting parts of the hinge are avoided, with the corresponding visual effect and reduction in the danger of injury. Adjacent slats are respectively equipped, approximately over the entire door width, with sealing strips which seal against wind and prevent penetration of rainwater and dust. These sealing strips, furthermore, ensure a mechanical stability of the slats relative to one another, so that, in the closed position, the slatted armor withstands even relatively high wind loads, without bulging or becoming deformed.
It is especially advantageous that the sealing strips engage within the slats in a direction perpendicular to the door leaf with little lateral play, so that, in the closed position, the slatted armor, when subjected to pressure, is immediately tensioned as a result of the bending of the sealing strips between slats bent to differing extents. The strips endeavor to counteract the pressure force, thereby again improving the mechanical stability. This lateral play is also selected so that a fault-free mounting of the slatted armor is guaranteed.
In a further embodiment of the invention, the sealing strips have thickened portions which engage into correspondingly designed recesses of the slats. This brings about a further increase in the mechanical stability of the slatted armor as a whole, with a correspondingly advantageous effect in terms of wind load and safety against unauthorized opening.
If the sealing strips are arranged coaxially relative to the hinge pins, the sealing strips are subjected only to bending stress during articulation of the slatted armor.
If, the sealing strips are such that mutually confronting supporting faces of the thickened portions are at a minimum distance, while enabling fault-free mounting from corresponding holding faces of the slats, it becomes possible that, in the closed position of the door, with a slat being subjected to pressure transversely to the door plane--after initial restoring forces solely as a result of bending stress on the sealing strips of the adjacent slats--a tensile stress on the sealing strips occurs immediately and prevents or limits a further bending out in relation to adjacent slats. Altogether, the slatted armor thus behaves largely in the same way as a homogeneous plane plate with a corresponding force distribution in the plate plane, but nevertheless allows low-force deflection.
An even steady running approximately friction free of the slatted armor is achieved by providing rollers running in the guide tracks mounted coaxially relative to the hinge pins.
An especially effective sealing closure of the door aperture is obtained by providing a sealing nose on the outside of each slat by means of which the distance between adjacent slats in the closed position is reduced, the slats remaining spaced from one another. Since the sealing strips cannot be seen from outside, a pleasing external appearance of the slatted armor in the form of a uniformly smooth surface is obtained at the same time.
In a further embodiment of the lifting door, sealing lips are arranged on the two mutually opposite sides of the door aperture, which project, in the closed position, as far as the position of the sealing strips in the plane of the door leaf and thereby prevent, not only the penetration of dust or dirt, but also unintentional insertion of the fingers and an accompanying danger of injury.
For further details, attention is drawn and reference is made to the full content of the two parallel German Patent Applications by the same applicant of today's date, entitled "Vertical Lift Gate with Strip Cladding," Ser. No. 08/259,050 and "Closure Element for an Aperture," Ser. No. 08/038,960.

BRIEF DESCRIPTION OF THE DRAWING FIGURES
Further details and expedient features of the invention emerge from the following description of an embodiment with reference to the Figures, in which:
FIG. 1 shows a partial side view of an exemplary embodiment of a lifting door according to the invention;
FIG. 2 shows a partial rear view of a slatted armor corresponding to the lifting door according to the invention;
FIG. 3 shows a diagrammatic sectional representation along the line III--III in FIG. 2;
FIG. 3A shows an enlarged representation of the detail X of FIG. 3;
FIG. 4 shows a top view of a slatted armor according to the present invention;
FIG. 5 shows a sectional side view of an exemplary embodiment of the lifting door according to the invention;
FIG. 6 shows a diagrammatic side view to illustrate the weight compensation of an exemplary embodiment of the lifting door according to the invention; and
FIG. 7 shows the characteristic of the weight compensation according to the invention as shown in FIG. 6.

As represented in FIGS. 1 and 4, the illustrated embodiment of a lifting door according to the invention has guide tracks 2 and 2' which are respectively arranged on the two mutually opposite sides 3 and 3' of a door aperture 1. Reference symbols followed by a (') are used to designate the corresponding parts of the lifting door which are arranged on the side 3'. Each guide track 2, 2' has a vertical portion 4 which extends vertically over the height of the door aperture and which extends approximately level with the lintel 6 and merges at the entrance 8 of the lifting door into an inwardly extending spiral portion 10 in an upper edge region of the door aperture. A slatted armor 12 for closing the door aperture having a door height h, is movable upwards into the spiral portion 10 of each guide track, when the door is moved into the open position, in such a way that the slatted armor is arranged spirally, and without slats 14 touching one another. An endless chain 16 and an electric motor 18 are provided as a drive for the slatted armor 12.
FIGS. 2, 3 and 4 show details of the slatted armor according to the invention. Provided on each of the two edge sides of the slatted armor 12 is a hinge strap 20, 20' which has a length corresponding essentially to the height of the door aperture 1. Hinge strap 20, 20' consists of rigid hinge members 22 which are connected to one another in an articulated manner and which can be angled relative to one another via hinge pins 24, 24'. For this purpose, each hinge member is shaped at its end in a known way to form a rolled-round lug, into which the hinge pin 24 can be inserted. Two respective adjacent hinge members are connected to one another in an articulated manner, in such a way that their lugs are arranged coaxially relative to one another, a common hinge pin 24 being mounted in the coaxial lugs.
Furthermore, in the example shown, rollers 26, 26' are mounted coaxially relative to the hinge pins 24, 24' and serve as rolling guidance for the hinge straps 20 and 20' in the guide tracks 2 and 2'. In the example illustrated, each guide track has a pair of round bars 28 and 30 arranged at a uniform distance from one another which is chosen to match the diameter of the rollers 26. The hinge straps 20, 20' and the round bars 28, 30 are produced, for example, from hard metallic material, whilst the rollers 26 can also be produced from plastic material. To prevent the slatted armor from falling out of the guide track, each roller 26, 26' has a holding collar 27, 27', the outside diameter of which is larger than the clear distance between the round bars 28, 30.
The slats 14 are attached and fastened to the hinge straps 20, 20', for example by means of screw connections 32, 32', in such a way that the resulting distance between the respective adjacent slats 14 forms a space 34, into which are disposed the hinge pins 24, 24' or the lugs surrounding the hinge pins and belonging to the hinge members 22, 22', as is shown best in FIG. 3. This is achieved, according to the invention, in that the geometrical axis of articulation 36 lies within the region which is limited by the two outer main surfaces 38 and 40 of the slatted armor 12. This position of the axis of articulation 36 ensures that the width of the angle opening between the adjacent slats 14 during the angling of the slatted armor is reduced to a minimum, so that the tilting accelerations during entry into the upper bent guide track are correspondingly reduced. The possible running speeds of the lifting door shown are thereby further increased, without this being accompanied by the generation of an excessive amount of noise.
The slats, having a height of, for example, 150 mm, are attached completely independently of one another and individually on the hinge straps 20, 20', so that, the absence of an entire slat does not affect the mechanical stability and functioning of the lifting door according to the invention. The hinge straps 20 and 20' thus form a supporting structure or skeleton for the slatted armor which absorbs all the forces occurring during the movement of the lifting door. Because of the mechanically continuous cohesion of the hinge straps 20, 20', the pulls or forces which occur are absorbed by the hinge straps 20, 20' and are not transmitted to the slats 14. Because the forces which arise are transmitted and distributed to an articulated continuous, but tension-resistant strap, a uniform and steady cycle of movement is achieved, even when the lifting door is running at extremely high speed.
Since the individual slats 14 are initially attached at a particular distance from one another on the hinge straps 20, 20', in order thus to make room for the hinge pin, the adjacent slats 14 have no contact with one another even in the closing position of the door, with the result that the rattling noises known in the conventional sectional door when the door is being closed are also eliminated completely in the lifting door according to the invention.
To increase the mechanical stability of the slatted armor and to increase the sealing, but without impairing the properties of the present lifting door as regards low noise generation, there are provided sealing strips 42 in the form of rubber strips which are arranged approximately over the entire door width between the hinge straps 20 and 20' and which connect mutually opposite sides of adjacent slats 14. Each sealing strip 42 is expediently arranged coaxially relative to the adjacent axis of articulation 36, so that, during the angling of the slatted armor 12 in the upper guide region, the sealing strips 42 are subjected only to bending stress. The sealing strips 42 engage with only little lateral play into the slats 14 in a direction perpendicular to the plane of the door leaf, so that the slatted armor 12, when subjected to pressure, is tensioned at a specific point and corresponding restoring forces immediately counteract the pressure load. Each sealing strip 42 has, on opposite sides, beads or thickenings 44 which engage in correspondingly shaped recesses 46 of the slats 14.
As can best be seen from the enlarged cut-out according to FIG. 3A, each thickening 44 has a supporting face 43 which is arranged opposite a corresponding holding face 45 of the slat 14. The distance between a supporting face 43 and the respective associated holding face 45 of the slat 14 is selected as small as possible--allowing for jam-free and fault-free mounting by insertion of the sealing strip 42 with the thickening 44 into the recess 46 from the side. Thus, in the closing position of the slatted armor, pressure loads possibly occurring on the slatted armor result in the sealing strip 42 being tilted to the side and, after the supporting face 43 begins to come into contact with the holding face 45, in the sealing strip 42 is subjected to tension relative to the two adjacent slats. In the event of even smaller deflections of the slat out of the plane of the door leaf, as long as the supporting face 43 does not touch the opposite holding face 45, the sealing strip 42 is subjected only to bending stress relative to the two adjacent slats, thus leading to corresponding restoring forces. Since the distance between the supporting face 43 and the associated holding face 45 is chosen to be a minimum, even when there are only small deflections, to ensure that the sealing strip is subjected to tension, the pressure loads occurring on the slatted armor are thus also transmitted and distributed from the initially directly affected sealing strip 42 to the adjacent sealing strips. Thus, in the event of a pressure load, the slatted armor according to the invention behaves largely in the same way as a homogeneous plane plate, with a corresponding force distribution in the plate plane, but with a slight deflection under low pressure forces. The sealing strips 42 therefore bring about an appreciable increase in the mechanical stability of the slatted armor, so that, in the closing position, the lifting door can withstand even high wind loads or other pressure loads easily.
Of course, the lifting door according to the invention also affords sufficient safety against unauthorized opening, so that the lifting door according to the invention comprises a permanent closure for the door aperture.
To prevent the slatted armor 12 from being pulled out, e.g., under high pressure forces, there are arranged on the two mutually opposite sides of the slatted armor holding collars 27, 27' which, in the exemplary embodiment illustrated, are designed as an outer disk having a diameter larger than the diameter of the rollers 26, 26'. The holding collars 27, 27' are slightly spaced from the adjacent supporting faces of the guide bars 28, 30, so that they bear against the outside of the guide bars 28, 30 for support only when the slats 14 bend very sharply under load, with the result that the slatted armor remains easily movable under relatively low pressure loads. Even under a load at particular points, the above-described force distribution via the sealing strip 42 in the plane of the door leaf prevents the holding collars 27, 27' of a loaded slat 14 from providing support prematurely as a result of the pronounced bending out of the latter and from thereby impeding the movement of the slatted armor.
In the exemplary embodiment shown in FIG. 3, each slat 14 has a sealing nose 48 which projects on the outside 38 in the plane of the door and by means of which the distance from an adjacent slat is reduced. Because of the sealing nose 48, the sealing strip 42 cannot be seen from outside in the closed position. The sealing strip 42 is then still visible only from the inside (see the rear view according to FIG. 2). At the same time, the design of the sealing nose 48, as shown in FIG. 3, results in a more pleasing appearance of the slatted armor 12 in the form of a more uniform smooth surface.
As protection for an individuals fingers and to prevent injuries caused by unintentionally touching movable parts, according to FIG. 4 there are provided respectively on the inside and outside of the door aperture sealing lips 50, 50' which, in the closed position, project as far as the position of the sealing strips 42 in the plane of the door leaf. The sealing lips located on the outside of the door aperture 1 form at the same time a seal against driving rain, dust or the like. These sealing lips can, for example, be produced from rubber.
A sealing lip 52 formed with a similar cross-sectional shape is arranged in the region of the lintel 6 (FIG. 5) and extends horizontally essentially over the entire width of the door aperture. The sealing lip 52 prevents rainwater or dirt from penetrating into the upper region of the lifting door.
To seal off the lifting door relative to the ground, according to FIG. 3 a closure 54, for example made of rubber, is provided and is fastened to the lowest slat.
As already explained with reference to FIG. 1, the lifting door according to the invention has the two guide tracks 2 and 2' in the upper region of the door and underneath the ceiling indicated by the reference symbol 55 formed, as a spiral portion 10 extending spirally inwards. In the open position of the lifting door, the slatted armor 12 is movable into the spiral portion in such a way that the plurality of slats are present in a spiral track and free of contact with one another. In contrast to the known rolling doors, in which the rolling armor is wound up on a winding shaft, according to the invention the slatted armor is always guided in such a way that the slats never touch one another. As a result, the pressure forces occurring in the rolling door on the slats are avoided completely, so that a correspondingly steady running allowing high speeds becomes possible. In contrast to the conventional sectional door, the upper guide track is not guided as a straight stretch directly underneath the ceiling, thus leading, particularly where larger door heights are concerned, to a considerable space requirement in terms of the depths of the door. In contrast to this, according to the exemplary embodiment shown in FIG. 1 the spiral portion 10 has the three arcuate portions 56, 58 and 60. As illustrated, part of the arcuate portion 60 bears directly against the arcuate portion 56, so that the inner radius of the arc 56 corresponds approximately to the outer radius of the arc 60. The outer radius of the arc 58 corresponds to the outer radius of the arc 56.
According to FIG. 1, the smallest possible occurring radius of curvature of the guide track 2 is equal to the radius of the innermost arc portion 60. This radius is selected so that a proper entry of the slatted armor 12 into the spiral portion 10 is possible in dependence essentially on the distance d between the adjacent hinge pins (see FIG. 3), without, for example, the fear of self-locking of the angled slats in the narrowest arc portion. A self-locking of this kind would occur at the latest when, during the entry of the slatted armor 12, a force component, directed parallel to the guide track, for overcoming the rolling friction at any point on the guide track becomes smaller than the rolling-friction component which acts correspondingly at this point and which is itself proportional to the normal force present at this point. In practice, however, the smallest possible arc radius is already limited by the fact that, during the angling of the slats, the sealing strips are bent, thereby generating restoring forces which have to be overcome by the drive of the lifting door and which are the greater, the narrower the selected guide arc.
The spiral arrangement of the guide track 2 utilizes the height g available above the lintel region to the best possible effect. The arcuate portions 56, 58, 60 can be standardized for all door heights occurring in practice, so that, irrespective of the particular door height, the lifting door according to the invention affords the advantage of a standard dimension for the height above the lintel. The adaptation of the total length of the guide track to the individual height of a particular user is guaranteed by separately insertable horizontal extension portions 62 of length a. In the instance shown, the length of the total guide track 2 is increased altogether by 3.times. a by the insertion of the extension portions 62. Since these portions constitute essentially the only parts of the lifting door which have to be manufactured or made available individually according to the door height, the lifting door according to the invention can be produced cheaply in large quantities and therefore also gain acceptance in more common uses outside the industrial sector.
Actual numerical values are indicated below for further illustration. At the current clear door heights of h=3 m, 4.5 m and 6 m, the values of the extension portions 62 correspond respectively to a=0 m, 0.5 m and 1 m. Thus, with a fixed value of the constructional height above the lintel of g=0.5 m, for an increase in the clear door height from 3 m to 6 m the space requirement in terms of depth increases only by 1 m. The diameter of the rollers 26 and therefore the clear distance between the guide tracks amounts to approximately 4 cm. In this arrangement, it is possible, for example, to open the door of height h=3 m completely in not less than 2 s.
According to FIG. 1, the electric motor 18, which is connected to a driving roller 64, is arranged in the free space remaining inside the spiral portion 10. The dot-and-dash line in FIG. 1 indicates diagrammatically the endless chain 16 which is driven by means of the driving roller 64 and the motor 18 and which chain is guided over deflecting rollers 66, 68, 70 (FIG. 5) and 72. Provided on the opposite side 3' of the door are deflecting rollers (not shown) which correspond to the deflecting rollers 68, 70, 72 and of which one deflecting roller is connected, for example via a coupling and a torsion shaft, rigidly in terms of rotation to the deflecting roller 72 and therefore serves as a gearwheel and drives a further endless chain (not shown). A further advantage of the lifting door according to the invention is that the torsion shaft constitutes the only constructional element which has to be made to order with an appropriate length in dependence on the desired door width.
In the region of a lower slat, the endless chain 16 is fastened to the slatted armor via a shackle 74. According to FIG. 5, the connection of the chain to the slatted armor is most expediently provided in such a way that the pull exerted during the upward movement of the slatted armor from the closed position to the open position runs completely within the plane of the door leaf, thus avoiding horizontally running force components which would lead to a tilting moment of the slatted armor, with the result that forces seeking to press the guides apart from one another would act on the guide tracks, whilst the rollers would be subjected to increased wear on account of the massive load.
Furthermore, the shackle 74 has, for example, a projecting rigid end 76 which, in the open position of the door, butts against a rubber buffer 78, attached above the lintel, without any substantial noise being generated.
According to FIG. 6, to adapt the pull acting on the drive of the lifting door to the particular weight of the free length of the slatted armor, a weight compensation 80 is provided and which has a compensating helical spring 82 and a band 84 fastened to spring 82 and consisting of a largely inelastic and tension-resistant material. The lower end of the compensating spring 82 is connected firmly to the ground. The band 84 is wound up via a deflecting roller 86 by means of a shaft 88 which interacts with the drive of the lifting door, for example via the deflecting roller 72 shown in FIGS. 1 and 5, specifically in such a way that, during the upward movement of the slatted armor, the band 84 is unwound from the shaft 88 and the spring 82 correspondingly relaxed. During the lowering of the slatted armor, the band 84 is wound onto the shaft 88, with a pull exerted correspondingly on the compensating spring 82, so that the latter is tensioned.
The shaft 88 has a predetermined core diameter, the value of which is selected so that, in dependence on the thickness of the band 84, the length L.sub.o of the compensating spring 82 at rest, the spring strength of the compensating spring 82 and the total weight of the slatted armor, with a desired characteristic of the weight compensation 80, as shown in FIG. 7, according to the door height is obtained.
In FIG. 7, for an illustrative clear door height of 3 m, the respective clear height of the remaining door aperture is plotted in millimeters on the right, the value "0 mm" representing the completely closed door and the value "3000 mm" representing the completely opened door, and to the top the total weight G.sub.T, acting on the drive, of the free slatted armor is plotted as a continuous line and the spring force F.sub.F likewise acting on the drive is plotted as a broken line. As can be taken from FIG. 7, the weight compensation 80 is set so that, with the door closed, the compensating spring is expanded until an excess spring force of approximately 260N over and above the weight of the slatted armor is provided. This ensures that, when the closed door is being actuated, the slatted armor also moves upwards without an additional drive approximately to the height at which the weight of the free slatted armor is in equilibrium with the corresponding spring force. In FIG. 7, this is represented by the point where the two lines intersect, that is to say at a height of approximately 1 m. During the further upward movement of the door, the respective weight is approximately in equilibrium with the acting spring force, so that the drive need take effect essentially only counter to the existing frictional forces. Further details can easily be taken directly from FIG. 7, without the need for further explanation.
For reasons of space, in the lifting door according to the invention, a weight compensation having at least one compensating spring is provided on each of the two sides of the door.
The weight compensation shown here has decisive advantages over the known solutions. In comparison with the torsion springs used in conventional sectional doors, the lifetime is markedly increased due to the use of a compensating spring in the form of a helical spring. The lifetime of a helical spring is approximately double the lifetime of a torsion spring. This reduces the problem of the complicated exchange of the power unit in the sectional door. Moreover, the lateral compensating springs 82 do not require any space above the lintel.
A further advantage of the weight compensation according to the invention emerges from the use of the band 84 which has a thickness of 2 mm in the instance shown. In comparison with this, if a wire cable were used, a further transmission, for example in the form of a loose roller would be necessary, since it would be possible to wind up a cable only in terms lying next to one another on a pulley, Specifically with a correspondingly larger core diameter. By contrast, according to the invention, the band can be wound up on a shaft stub of relatively small core diameter so that additional transmission means is not required. Moreover, the band is wound up with turns lying above one another, so that the winding radius quickly becomes larger, as desired, starting with the open position of the door, but, with the roll wound up approximately completely in the closed position of the door, now changes only a little.
As can easily be seen, the main advantages which can be achieved with a special type of weight compensation described have particular importance in combination with the further features of the present invention, but they also plainly have independent importance, since these advantages can otherwise be used independently of details of the design of the door.

Number	Name	Date
2214653	Barlough	Sep 1940
3148724	Chieger et al.	Sep 1964
3302690	Hurd	Feb 1967
3516469	McDonald	Jun 1970
3608613	Halliwell	Sep 1971
3878879	Manns	Apr 1975
3891021	Geoffrey	Jun 1975
4345635	Solomon	Aug 1982
4893666	Hormann	Jan 1990
4947937	Searer et al.	Aug 1990
5025847	Mueller	Jun 1991
5394924	Rejc	Mar 1995

Lifting door with a slatted armor having articulated slats

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