CA2078853A1 - Lift-type door having a slatted shutter in guide tracks - Google Patents

Abstract

Abstract 1. Lift-type door having a slatted shutter in guide tracks.

2.1. The prior art rolling shutter doors employed as covers for a door opening, in which the door leaf is laterally guided and vertically raised, exhibit only inadequate high-speed operating properties owing to their design, and cause excessively high noise emission when in operation.

2.2. The lift-type door according to the invention comprises two guide tracks (2, 2'), which are arranged at the two opposing sides (3, 3') of the door opening (1), and a slatted shutter (12) with slats (14) mounted with an intermediate clearance in each case on hinge straps (20 20') such that the joint pins (24, 24') engage within a space (34) between the adjacent slats (14).

2.3. Application of the lift-type door as a high-speed door.

3. Fig. 1.

Description

2~ 3853 Description Lift-type door having a slatted shutter in guide tracks The invention concerns a lift-type door with a slatted shutter which can be moved in guide tracks vertically upward from a closed position to an open position in relation to a door opening.

A known example of such a lift-type door is a rolling shutter door which serves as a vertically actuated closure for a door opening allowing passage of persons or traffic and which conventionally consists essentially of a rolling shutter comprising slats which can be angled with respect to one another, which are guided along the two side edges of the door opening by means of vertical guide rails for movement into the closed position, a winding shaft to which the rolling shutter is secured and by means of which the rolling shutter is moved up into the open position and wound, an electric motor drive, and an arresting device which prevents the rolling shutter from dropping in the event of failure of the drive.

The rolling shutter, as the part of a rolling closure which closes and protects the door opening, consists of slats which are connected to each other by articulated joints, such slats as a rule taking the form of profile elements, e.g. extruded aluminium materials. The height of the individual slats, as a rule, ranges between approx. 80 and approx. 120 mm in such cases. These profile elements are mostly provided in the form of slide-in profiles which, due to their shape, can be pivot-connected to each other without additional connecting elements to form the rolling shutter. In the case of a typical aluminium extrusion, the joint, for example, takes the form of a rolled bead and groove arrangement so that when one slat is slid into another, :, the joint thus formed is able to absorb and withstand the forces which arise as the rolling shutter is wound. The slat connection forming an articulated joint invariably features a large clearance. Moreover, the shape of the interlinked slats is intended such that dirt and water are prevented from becoming lodged in the joints, and so that there is sufficient tightness against wind attack.

The wound layers on the winding shaft are formed by the interlinked profiles which have a certain profile height. Each profile lies on the foremost edge of a profile of the layer located below. The direction assumed by a profile in the wound cross section within its layer is determined by the point of support of the profile. Owing to its randomly assumed position, this profile in turn has an effect on the arrangement of the next profile to which it is connected. As a result, the wound layers are characterized by irregular arrangement of the individual rolling shutter door profiles. One consequence, inter alia, of this is that, for example, only a single edge of a single rolling shutter door profile supports the entire load of the still suspended part of the shutter, as a result of which considerable edge pressures can arise.

To protect against lateral displacement, head pieces or end pieces are, as a rule, mounted on the side of the rolling shutter door profiles, said head or end pieces running in corresponding vertical guide rails having, as a rule, a channel cross section.
These vertical guideways are funnel-shaped at their top inlet, so that the rolling shutter is able to run efficiently into the vertical guide during unwinding without any danger of catching.

The rolling shutter is secured to the winding shaft by its first profile so that, when the door is closed, the mounting is located on the side of the shaft opposite to the shutter, i.e. so that the shutter or the end plates extending the shutter are wrapped around the shaft by at least 180. This has the effect that the shutter is extensively held by frictional forces so that the full 2~ ~ 3~

deadweight of the shutter is not applied to the suspension mountings. The door is closed when the bottom end profile is rest:ing on the bottom edge of the opening, i.e. in general on the floor. The rolling shutter should, moreover, not undergo any buck:Ling. The entire shutter -apart from the bottom end profile -therefore remains suspended as a load on the shaft or shaft axle~ This signifies a fundamental difference between the rolling shutter door and the rolling blind, the latter being usually provided as an additional closure of an opening.

In the open position of the rolling shutter door, the rolling shutter wound on the winding shaft lies in the lintel area of the door opening. The drive is usually located in a protected position behind the lintel and can thus not be damaged by vehicles passing through the door opening. As a rule, an electric motor is provided for the drive, with a manually operated actuator also being provided as a standby drive.

With an electric drive, the rolling shutter door shaft is driven at constant speed, i.e. at a uniform angular velocity. As a result, the rolling shutter secured to the shaft is raised and wound onto the shaft. The speed of elevation is decisively influenced, in the first instance, by the currently prevailing winding radius, a dimension which is continuously increased as winding proceeds because the lower portions of the rolling shutter lie on the already wound upper portions. As the elevating velocity changes in direct proportion to the wound radius, a rolling shutter door is initially raised slowly and then continuously gathers speed as its moves upward. Closer scrutiny of the kinematic conditions, taking into account the thickness and height of the profiles, reveals that the wound rolling shutter door must be regarded as a polygon. During winding, the profiles lie initially on the round winding shaft. On this the straight profiles form a polygon. The corners of the polygon are further from the shaft centre than the centers of one polygon side. If the shaft of the rolling shutter door now turns at a constant angular velocity, the rolling shutter is initially 4 2~ 5.3 raised by a lever arm corresponding to the length up to the vertex of the polygon at the elevating velocity corresponding to this lever arm length, and in the next moment by a lever arm corresponding to the length up to one side of the polygon at the elevating velocity corresponding to this dimension. The elevating velocity is directly proportional to the currently prevailing lever arm dimension, which is non-steady and irregular, and is thus characterized by correspondingly substantial and sudden variations as the rolling shutter is wound. This phenomenon is accompanied by mass accelerations and decelerations of varying intensity in respect of the still unwound rolling shutter mass.
These mass accelerations also affect the gearing of the drive motor, and the gearing must therefore be designed for a corresponding degree of cyclic variation as otherwise failures may occur. It is true to say that these acceleration variations, in principle, become less pronounced as the thickness of the wound rolling shutter door cross section increases, i.e. the more the polygon approximates to a circle. However, as the greatest mass accelerations and decelerations occur when the rolling shutter is still well down in the doorway, the forces which occur are further increased by virtue of mutual multiplication owing to the not inconsiderable deadweight of the rolling shutter.

The accelerations and decelerations of the masses of the unwound rolling shutter have the effect of oscillations. These oscillations are transmitted not only to the winding shaft but also through it to the structure so that, in the static analysis and design of the structure, it is necessary to ensure that the natural frequency of the structure lies outside the rolling shutter door frequency range. Otherwise the elevating velocity of the rolling shutter door has to be drastically reduced. Under conditions of uniform angular velocity of the rolling shutter door shaft, the frequency of the oscillations increases and their amplitude decreases as the thickness of the wound rolling shutter door cross section increases. Conversely, this means that noise emission during operation of the rolling shutter door increases as the rolling shutter comes down.

Aside from the above-indicated irregularities in lever arm lengt:hs which occur during winding of the profiles in the form of polygon sides, there is a further phenomenon in the case of prior art rolling shutter doors which likewise leads to extremely prob].ematical kinematic conditions. As the driven shaft of a rolling shutter door cannot exert any compressive forces on the rolling shutter, it must be ensured that, in the raised state, the drop weight of the freely suspended portion of the rolling shutter with its bottom rail is greater than the prevailing static friction. Only thus does the shutter automatically put itself into motion as a result of its own weight when the shaft is driven in the unwinding direction. The level of static friction in the case of the shutter is at its lowest when, in its raised state, it runs vertically into the guides. This attitude is termed the "normal starting position". As the rolling shutter runs out, the wound diameter decreases. The shutter then runs at an increasingly acute angle into the inlets of the guideways.
Once the rolling shutter has completely unwound but - as is usual with rolling shutter doors - is still suspended under tension from the shaft, the entire load of the rolling shutter is suspended, under certain circumstances, from only a single profile of the profiles still located on the shaft. Scrutiny of a vertical cross section through a rolling shutter door reveals that the tensile force of the entire deadweight of the shutter lies not in the door plane but rather in the straight-line connection from the underpiece to the effective wound radius. The rolling shutter will therefore deform at the centre between the guideways in order to approximate as far as possible to the prevailing pattern of tensile stress. The profile ends, however, are held by the guideways and cannot follow the tensile stress line. While the tensile stress resulting from the rolling shutter deadweight pulls the top of the shutter out of the door plane toward the shaft, the guideways bend the profile ends back toward the door plane. As a result, the individual profiles are not only subjected to bending stress but also to torsion, with the greatest bending and torsional moments occurring at the inlet.

6 2 ~ 5 ~
In order to reduce the sealing problems which accampany the "normal starting position" type of location, a proposal was made to limit the degree of flexion by fitting a pressing shaft. Such a solution, however, also involves a more unsteady and noisier rolling shutter door operation (cf. Horst Gunter Steuff, "Das Rolltor", Dusseldorf, Werner Verlag GmbH, 1987, p. ~3).

The unfavorable kinematics described above of the rolling shutter door which, in terms of its fundamental characteristics, has been in existence for more than a hundred years (and to date has hardly undergone any change) can be regarded as the main reason for a high level of noise emission during operation, and in the final analysis also for the inadequate high-speed properties of the rolling shutter door. The operating noises which essentially emanate from the profile joints occur mainly during the upward cycle of the rolling shutter door, and in particular during the bottom third of the door opening, in as much as the rolling shutter door exhibits a "normal starting position". The noises arise in the vicinity of the passageway where the profiles flex, are loaded by tensile forces, and yet have to turn around their joint axes.

Although the prior art rolling shutter door, owing to its non-positive and positive interlocking slat connections, has long been regarded as an inexpensive solution in terms of providing tightness against wind pressure and security against unauthorized opening, the poor high-speed running qualities of the conventional rolling shutter door were quickly identified as disadvantageous for industrial door applications. The operating speeds of the conventional rolling shutter door range between approx. 0.25 and 0.35 m/s.

In the industrial sector, high-speed rolling doors with a one-piece door leaf of flexible material which can be rolled onto a winding shaft or winding drum have proven successful as an additional closure element for openings. Suitable selection of the flexible material also enables such rolling doors to offer 7 Z~? ~
the advantage of optical transparency. Macrolon sheets or plasticized PVC sheets, for example, are widely employed. This advantage over non-transparent material, however, becomes lost with time because the optical transparency is adversely affected by dust and similar materials being entrained as the sheet is wound, with the surface becoming scratched and opaque as a consequence.

In view of the limited space availability above the lintel area and the large initial shaft diameter common to rolling sheet doors, the sheets in this type of rolling door must be as thin as possible, because the total wound diameter would otherwise be too large. Moreover, the provision of thin sheets also facilitates faster operation of the door leaf owing to its easier windability. The small thickness of the sheets, and correspondingly low deadweight of the door leaf, nowever, lead to a reduction in wind resistance. In order to alleviate this problem, it was proposed that an additional weight be provided in the form of a termination profile arranged at the bottom edge of the door leaf, or that spring-loaded tension belts be provided which run around idler rollers mounted at the floor.

The greatest disadvantage with rolling sheet doors is consequently derived from the behavior of the door leaf under wind pressure, which is more akin to the behavior of a sail than to that of a plate. As the door leaf is only supported by the winding shaft, the door leaf under wind load undergoes considerable billowing and bulging and can, conse~uently, also be raised off the ground. Such rolling doors, in view also of the lack of security against unauthorized opening, can only be considered as an additional closure for a door opening.

Sectional doors are also known as closure elements for large doorways. A conventional sectional door consists essentially of a shutter with relatively high sections which can be raised by means of a hoist drive from a vertical closure position to an upper horizontal position below the ceiling.

8 x~ ~
Owing to the relatively large height of the individual sections in sectional doors and the reduced number of section connecting elements such as hinges or similar, and a concomitant reduction in t]le number of meeting edge faces which have to be sealed, an overall more compact mechanical construction is achieved with correspondingly good strength against wind attack and better security against unauthorized opening. Moreover, the large height of the individual sections allows the provision of transparent sections in the form of glass or plastic windows.

The compact construction of sectional doors further enables the provision of lightweight doors of aluminium sections which, for the purpose of thermal and sound insulation, may for instance be filled with a plastic material so that, for example, garage doors, including those with relatively large door widths, can be manually opened and closed without the aid of an additional electric motor drive.

As a rule, the individual sections are flush to one another in the closed position, so that the full meeting edge face of each section is available for the seal. The sectional door thus has the appearance of a tightly closed door with a continuous external surface and without any intermediate gaps. A further improvement in tightness is achieved, for example, by rubber inserts which, in the closed position, are pressed together by the sections resting on top of one another. As an alternative, the sections may feature a convexity along one meeting edge face across the full width of the door, which convexity engages in a corresponding recess in an adjacent section as the sections are swung into the same plane, similar to a tongue-and-groove joint, thus further improving the mechanical resistance of the door leaf to wind pressure, even in the case of large door widths.

on the inside of the door, the sections are connected by means of a number of individual hinges which are arranged across the entire width of the door at certain intervals in a quantity that provides sufficient strength and support. The hinges at the side 2~7~353 edge of the sections are, as a rule, also designed as a mounting for a roller which can run in a guide rail of channel cross section arranged along the side edge of the sectional door. As the individual hinges at the sections are arranged such that the sections can be folded away toward the interior, problems arise in that the protruding parts of the hinges arranged on the inside of the door impair the visual appearance of the door and constitute an injury hazard. A further injury hazard arises in the case of sectional doors when the sections are angled, owing to the open gaps which then occur and which are then closed again when the sections are folded back.

A further disadvantage found in sectional doors with relatively high sections relates to the bow-shaped guide section above the lintel area where the individual sections are diverted from the vertical plane to the horizontal plane. This diversion naturally leads to sudden tilting accelerations and correspondingly, with fast actuation, to considerable forces being applied to the individual sections. Owing to the different radial distances of the guide rollers to the actual position of the mass of the section in the area of the top curved path, acceleration and deceleration forces occur, with a generally irregular force pattern resulting from the flat shape of the sections of finite height located in the curved path along the lines of a polygon.
This means that sectional doors as a rule can only be operated at relatively low speeds if the danger of high noise emission is to be avoided.

The transmitted transverse forces are also absorbed by the body of the sections via a number of individual hingea, so that the sections are loaded. The forces transmitted to the end hinges and correspondingly, to the guide rails as the sections are diverted, are essentially dependent upon the speed at which the sectional door is opened and closed. owing to the construction of the sectional door, which in principle is not designed for high speeds, there are limits to the application of sectional doors as industrial doors with a high-speed capability.

lo 2~ 53 The drive system provided as a rule for sectional doors takes the form of a rope hoist with traction ropes and support ropes, and rope drums arranged on a drive shaft. During the upward cycle of the door, the support ropes are wound onto the rope drums, while simultaneously the traction ropes are unwound from the rope drum.
During the downward cycle of the door, the traction ropes are wound, thus pulling the door down, while simultaneously the support ropes are unwound, without becoming slack, from the rope drums. The support ropes are thus continuously under tension and cannot unravel from the rope drums. The drive for the drive shaft is provided by an electric motor which, for example, may be arranged directly below the ceiling.

A known method for counterbalancing the weight of the door leaf is to provide torsion springs which are arranged coaxially relative to the drive through-shaft. In the closed position of the door, the torsion springs are fully stressed, and are correspondingly relaxed as the door leaf rises. These torsion springs are subjected to elevated wear and are thus substantially limited in terms of their service life. Particularly in the case of frequent and sudden changes in the direction of movement of the sectional door, the torsion springs suffer from considerable dynamic peak stresses due to the transient motions involved. The maintenance and replacement work resulting from the failure of the torsion springs in the case of sectional doors is naturally time-consuming and complicated.

Owing to the arrangement of the drive shaft with the torsion springs above the guideway bend, and the proximity of the electric motor to the drive shaft r considerable space has to be provided above the lintel in the case of conventional sectional doors, which, without special structural measures such as, for example, the provision of a double horizontal guide arrangement below the ceiling, or positioning the drive shaft together with the torsion springs at the extreme end of the guide rails, is unlikely to be below a typical value of 400 mm. In addition there is the excessively large depth requirement of sectional doors X~ 53 which essentially corresponds to the clear height o~ the door opening. As the free depth available as a rule, i.e. the distance between the rear edge of the lintel and the next obstacle toward the back of the room, such as a joist, wall, ventilation pipe, fan or similar, may be small, the installation of a prior art sectional door may in many cases be impossible.

The object of the invention is to make a lift-type shutter door available which can be opened and closed at high speed with little noise emission, which, in its closed state, offers sufficient tightness against wind and weather attack and security against unauthorized opening, and which, moreover, only has a small space requirement above the lintel, even in the case of relatively high doors.

This object is achieved by a lift-type shutter door with the characteristics claimed in claim 1.

In the case of the lift-type door according to the present invention, the two guide tracks, which are arranged at the corresponding two opposing sides of the door opening, are designed such that, starting at a vertical section running vertically approximately over the height of the door opening, the two guide tracks converge at the inlet of the lift-type door into a helix-shaped, inwardly directed spiral section. As a result, the space required for the slatted shutter in its open position in the depth direction of the door is minimized, even in the case of a relatively high door opening, without substantially increasing the space requirement in the vertical direction above the lintel. According to the invention, in the open position of the lift-type door the slatted shutter can be moved into the spiral section of the guide tracks such that a plurality of slats are stored in the helix-shaped track without coming into contact with one another, thus resulting in no frictional forces or pressures being applied to the slats, and therefore enabling substantial lift-door operating speeds without these being accompanied by excessive noise emission. The slats of the slatted 2~ 5~3 shutter which cover the width of the door opening are angleable relative to one another and manufactured from rigid material so that the lift-type door in its closed position exhibits sufficient mechanical stability in order to withstand even relatively high wind loads, and in order to ensure security against unauthori%ed opening.

As claimed in claim 2, extension sections are provided for adaptation to the various door heights, said extension sections being simply installed essentially horizontally in the spiral section of the guide tracks.

In a further development of the invention, as claimed in claim 3, the guide tracks are provided in the form of a pair of round section rods, as a result of which, in particular, the bow-shaped sections of the guide track can be fabricated with ease.

As an improvement to the drive of the lift-type door according to the invention, a weight balance is provided as claimed in claim 4, which weight balance features a balance spring and a belt secured to the said balance spring, which belt can be wound on a shaft which interacts with the drive of the lift-type door, said shaft exhibiting a predetermined initial diameter. The main advantages of this weight balance lie, in particular, in an extended service life of the weight balance without the need for additional transmission or traversing means in order to achieve the required operating characteristic.

The drive offering advantages in terms of the possible operating speeds of the lift-type door according to the invention features, as claimed in claim 5, a continuous chain which can be driven by an electric motor, said continuous chain being secured at a point on the slatted shutter. The continuous chain is guided such that the tensile forces applied during the raising and lowering of the slatted shutter are completely distributed in the plane of the door leaf.

As claimed in claim 6, a sealing lip arranged horizontally across virtually the entire door width is provided as a top closure of the cloor opening, by means of which sealing lip rain water, dirt and similar are prevented from penetrating into the upper area of the lift-type door.

With respect to further details, reference is made to the two co-pending German patent applications of the present assignee entitled "Lift-type door having a slatted shutter with angleable slats" (agent's reference 61EF01562) and "Closure element for an opening" (agent's reference 61EF01582) filed on the same day, the full contents thereof being hereby incorporated by reference.

Further details and useful features of the invention derive from the following description of an embodiment in which reference is made to the following figures:

Fig. 1 shows a partial elevation of an embodiment of the lift-type door according to the invention;
ig. 2 shows a partial rear view of a slatted shutter corresponding to the lift-type door according to the invention;
ig. 3 shows a schematic cross-sectional drawing along the line III-III in Fig. 2;
ig. 3A shows an enlarged representation of detail X from Fig.
3;
ig. 4 shows a plan view of a slatted shutter according to the present invention;

Fig. 5 shows a cut-away elevation of an embodiment of the lift-type door according to the invention;

2~;7~53 ig. 6 shows a schematic elevation to illustrate the weight balance arrangement of an embodiment of the lift-type door according to the invention.

As Fig. 1 and Fig. 4 illustrate, the depicted embodiment of a lift-type door according to the invention features guide tracks 2 and 2' which are arranged at the two opposing sides 3 and 3' of a door opening l. In the following, accented reference characters shall designate in each case the corresponding parts of the lift-type door which are arranged at side 3' of the opening 1, so that in the following no further express mention need be made of this fact. Each guide track 2, 2' features a vertical section 4 running vertically along the height of the door opening, which vertical section 4 extends to approx. the height of the lintel 6 and then converges at the inlet 8 of the lift-type door into a helix-shaped, inwardly directed spiral section 10 in an area above the top edge of the door opening. A slatted shutter 12 for covering the door opening of clear door height h in the closed position can be moved upward into the spiral section 10 of each guide track to the open position of the lift-type door so that the slatted shutter is stored in a spiral arrangement without any adjacent slats 14 coming into mutual contact. A continuous chain 16 and an electric motor 1~ are provided as the drive system for the slatted shutter 12.

Details of the slatted shutter according to the invention are illustrated in Figs. 2, 3 and 4. Arranged at each of the two side edges of the slatted shutter 12 are hinges in the form of hinge straps 20, 20' of a length which essentially corresponds to the height of the door opening 1. Each hinge strap 20, 20' consists of rigid hinge elements 22 which are linked to each other and can be angled with respect to one another by joint pins 24, 24'.
For this purpose, each hinge element has been rolled in the ~t conventional manner to form an eye at its end into which the ~oint pin 24 can be inserted. Each pair of adjacent hinge elements are linked together such that their eyes are coaxially arranged to each other and in which eyes a common joint pin 24 is located.

In the illustrated example, moreover, rollers 26, 26' are mounted coaxially relative to the joint pins 24, 24', said rollers 26, 26' providing rolling guidance of the hinge straps 20 and 20' in the guide tracks 2 and 2'. In the depicted embodiment, each guide track features a pair of round section rods 28 and 30 which are arranged at a uniform distance from one another, said distance being selected to suit the diameter of the rollers 26. The hinge straps 20, 20' and the round section rods 28, 30 are, for example, manufactured from hard, metallic material, while the rollers 26 may also be manufactured from plastic material. To secure the slatted shutter against detachment from the guide track, each roller 26, 26' features a retaining flange 27, 27', the outside diameter of which is greater than the clear distance between the round section rods 28, 30.

The slats 14 are, for example, located and secured by means of bolts 32, 32' on the hinge straps 20, 20' so that a space 34 is formed by virtue of the distance which arises between adjacent slats 14, in which space 34 the joint pins 24, 24', or the eyes of the hinge elements 22, 22' surrounding the joint pins, engage as best illustrated in Fig. 3. According to the invention, this has the effect of ensuring that the geometrical axis of rotation 36 comes to rest completely within the zone which is limited by the two outside main surfaces 38 and 40 of the slatted shutter 12. The location of the axis of rotation 36 in this position ensures that the width of the angle opening between adjacent slats 14 during angling of the slatted shutter is reduced to a minimum dimension so that, correspondingly, the tilting accelerations during travel into the top, bent-away guide track are reduced. As a result, the possible operating speeds of the lift-type door shown are ~urther increased without being accompanied by excessive noise emission.

The slats with a height of, for example, up to 150 mm are mounted quite independently of one another and individually on the hinge straps 20, 20', so that, for example, the lack of a complete slat has no effect on the mechanical stability and operability of the lift-type door according to the invention. The hinge straps 20 and 20' thus constitute, to a certain extent, the bearing structure or skeleton of the slatted shutter, which bearing structure absorbs all the forces arising from the move~ent of the lift-type door. Owing to the fact that the hinge strap 20, 20' is a continuous mechanical assembly, the tensile forces which arise are absorbed by the hinge straps 20, 20' and not transmitted to the slats 14. By virtue of the transmission and distribution of the forces which occur to an articùlate, continuous yet rugged strap of high tensile strength, uniform and quiet operation is achieved even under conditions of extremely fast door actuation.

As the individual slats 14 are initially mounted on the hinge straps 20, 20' at a certain distance from one another in order to create room for the joint pins, adjacent slats 14 also remain non-contacting in respect of one another in the closed position of the lift-type door according to the invention, thus completely avoiding the rattling sounds which commonly occur when a conventional sectional door is closed.

In order to enhance the mechanical stability of the slatted shutter and increase its draught exclusion properties, without, however, jeopardizing the properties of the present lift-type door in relation to lower noise emission, sealing strips 42 in the form of rubber strips are provided which are arranged virtually across the entire width of the door between the hinge straps 20 and 20', and which connect meeting edge faces of adjacent slats 14. Each sealing strip 42 is arranged suitably coaxially relative to the adjacent hinge rotary axis 36, so that 2~?7~/~,5~3 the sealing strips 42 are only subjected to bending stress when the shutter 12 is angled in the top guide section.

The sealing strips 42 engage in the slats 14 with only minimal lateral clearance in the direction perpendicular to the door leaf plane, so that the slatted shutter 12, subjected to a pressure load at a certain point, is placed under tension and correspond-ing restoring forces immediately counter the pressure load. Each sealing strip 42 features, on opposite sides, beads or enlargements 44 which engage in correspondingly shaped recesses 46 of the slats 14.

As best illustrated by the enlarged detail in Fig. 3A, each enlargement 44 features a support face 43 which is arranged opposite a corresponding retaining face 45 in the slat 14. The distance of a support face 43 to its associated retaining face 45 in the slat 14 is - taking into account the requirement of smooth and trouble-free assembly by insertion, from the side, of the sealing strip 42 with the enlargement 44 in the recess 46 -kept as small as possible so that, in the closed position of the slatted shutter, any pressure loading against the slatted shutter which might arise results in the sealing strip 42 being tilted to the side and, once contact has oGcurred between the support face 43 and the retaining face 45, the sealing strip 42 of the two adjacent slats is subjected to tensile stress. In the case of still smaller displacements of the slat concerned out of the door leaf plane, iOe. as long as the support face 43 does not come into contact with the associated retaining face 45, the sealing strip 42 of the two adjacent slats is merely subjected to bending stress, which leads to corresponding restoring forces.
As the distance between the support face 43 and the associated retaining face 45 is kept minimal so that, where possible, the sealing strip is subjected to tensile stress even under conditions of small displacements, the pressure loads which arise and to which the slatted shutter is subjected are transmitted and distributed from the initially immediately affected sealing strip 42 also to the adjacent sealing strips. In the event of pressure ~? t'~

loading, the slatted shutter according to the inv~ntion thus beha~es extensively like a homogeneous flat plate with corresponding force distribution in the plate plane, while at the same time permitting a low-force diversion operation. Thus the sealing strips 42 result in an appreciable increase in the mechanical stability of the slatted shutter, so that the entire lift-type door in its closed position also withstands high wind or other pressure loads without difficulty.

Needless to say, the lift-type door according to the invention also offers sufficient security against unauthorized opening, so that the lift-type door according to the invention can be regarded as a durable means of keeping a door opening covered and closed.

In order to protect the slatted shutter 12 from detachment in the event of the possible occurrence of even greater pressure loads, retaining flanges 27, 27' are arranged at the two opposite sides of the slatted shutter, which retaining flanges 27, 27' in the depicted embodiment take the form of an external ring of greater diameter than the diameter of the rollers 26, 26'. The retaining flanges 27, 27' are arranged with a small clearance (not shown in detail in the drawing) in respect of the adjacent support surfaces of the guide rods 28, 30 such that they only come into contact with the guide rods 28, 30 in the event of very substantial bending of the slats 14 under load; the slatted shutter thus remains easy to operate and move under conditions of relatively small pressure loads. The good distribution of forces in the door leaf plane brought about by the sealing strip 42 as already described also prevents the retaining flanges 27, 27' of a slat 14 under load from coming into early contact with the guide rods 28, 30 as a result of substantial bending of said slat 14, and thus from inhibiting the movement of the slatted shutter.

In the case of the embodiment shown in Fig. 3, each slat 14 features a sealing projection 48 on the outside 38 of the door 1 9 ~? ~
leaf plane, by means of which projection 48 the distance to an adjacent slat is reduced. Owing to the presence of the sealing projection 48, the sealing strip 42 can no longer be identified from the outside when the slatted shutter 12 is in its closed position. The sealing strip 42 can then only be seen from the inside (see rear view, Fig. 2). At the same time, owing to the shape of the sealing projection 48 shown in Fig. 3, the appearance of the slatted shutter 12 is more appealing by virtue of a more uniform, smooth surface.

As a finger protection and thus as a means for preventing injury resulting from unintentional contact with moving parts, the inside and the outside of the door opening are provided with sealing lips 50, 50', as shown in Fig. 4, which in the closed position of the door extend to the position of the sealing strips 42 in the door leaf plane. The sealing lips located on the outside of the door opening 1 also form a seal against driving rain, dust or similar. The sealing lips may, for example, likewise be manufactured from rubber.

A sealing lip 52 of analog cross-sectional form is arranged in the area of the lintel 6 (Fig. 5), where it runs horizontally over essentially the entire width of the door opening. Sealing lip 52 prevents rainwater or dirt from penetrating the top area of the lift-type door.

The bottom seal of the lift-type door is, according to Fig. 3, provided by a termination strip 54, for example of rubber, which is secured to the bottom-most slat.

As already explained with the aid of Fig. 1, the lift-type door according to the invention features the two guide tracks 2 and 2' which, at the top of the door and below the ceiling indicated by reference 55, take the form of a helix-shaped inwardly running spiral section 10. In the open position of the lift-type door, the slatted shutter 12 can be moved into the spiral section such that a plurality of slats is stored in the helix-shaped track without coming into contact with one another. In contrast to the prior art rolling shutter door, in which the rolling shutter is wound on a winding shaft, the slatted shutter according to the invention is always guided such that the slats never come into contact. As a result, the forces of pressure which are placed on the slats in the case of the rolling shutter door are completely avoided, thus enabling a correspondingly quiet operation which permits high travel speeds. In contrast to the conventional sectional door, the upper guide track does not take the form of a straight section arranged directly below the ceiling, a solution which, in the case of larger door heights, leads to a considerable space requirement along the depth of the doorway.
Instead, the spiral section 10 in accordance with the embodiment shown in Fig. 1 features three curved sections 56, 58 and 60. As illustrated, a portion of the curved section 60 is in immediate proximity to curved section 56, so that the inside radius of curve 56 approximately corresponds to the outside radius of curve 60. The outside radius of curve 58 corresponds to the outside radius of curve 56.

As shown in Fig. 1, the smallest possible radius of curve which occurs in the guide track 2 is equal to the radius of the innermost curve section 60. This radius has been selected so that orderly insertion of the slatted shutter 12 in the spiral section 10 is possible, as essentially governed by the distance d between adjacent joint pins (Fig. 3), without, for example, any fear of the angled slats becoming jammed in the tightest curve section.
Such a jamming phenomenon would occur, at the latest, if, on entry of the slatted shutter 12, the force component running parallel to the guide track, which is required for overcoming the rolling friction at a given point in the guide track, becomes smaller than the rolling friction component which is correspondingly effective at this point, this rolling friction component in turn being proportional to the normal force present at this same point. In practice, however, the smallest possible curve radius is already limited by the fact that, when the slats are angled, the sealing strips are bent, as a result of which 2~ 5~3 restoring forces arise which have to be overcome by the drive of the lift-type door and which increase in magnitude with increasing tightness of the guide track bend radius.

As a result of the spiral arrangement of the guide track 2, the exist:ing height g above the lintel area is optimally utilized.
The curve sections 56, 58, 60 can be manufactured on a standardized basis for all the door heights which occur in practice, so that, irrespective of the door height concerned, the lift-type door according to the invention offers the advantage of a uniform dimension for the height above the lintel.
Adaptation of the overall length of the guide track in accordance with the user-specific individual door height is ensured by separately installable, horizontally running extension sections 62 for the length a. In the depicted case, the length of the entire guide track 2 is increased by inserting the extension sections 62 for a total of 3 x a. As these extension pieces essentially constitute the only components of the lift-type door which have to be individually manufactured and provided according to the door height, the lift-type door according to the invention can be manufactured in large batch quantities with concomitant advantages of scale, thus rendering it readily acceptable for more every-day uses outside the industrial sector.

For further illustration and clarification, concrete numerical values are offered in the following. In the case of the usual clear door heights of h = 3 m, 4.5 m, 6 m, the values for the extension sections 62 in each case are a = 0 m, 0.5 m, 1 m, respectively, so that, given a fixed value for the structural height above the lintel of g = 0.5 m, an increase in the clear door height from 3 m to 6 m results in an increase in the space requirement in the depth direstion of just 1 m. The diameter of the rollers 26, and thus the clear width of the guide tracks, in this case is approx. 4 cm. With this arrangement it is possible, for example, completely to open a door with a height h = 3 m in no less than 2 s.

22 2~?~J~5 ~
According to Fig. 1, the electric motor 18 is arranged in the space inside the spiral section 10, said electric motor 18 being connf!cted to a drive pulley 64. The dash-dot line in Fig. 1 represents schematically the continuous chain 16 which is driven by the drive pulley 64 and the motor 18, and guided around pulleys 66, 68, 70 tFig. 5), and 72. On the opposing side 3' of the door are pulleys (not illustrated) corresponding to pulleys 68, 70, 72, of which one pulley, for example, is rigidly connected by a coupling and a torsion shaft with pulley 72, which is designed as a gear wheel, and which drives a further continuous chain (not illustrated). At this point a further advantage of the lift-type door according to the invention should be noted in that the only component of which the length has to be altered on the basis of individual order data is the torsion shaft, this having to be adapted to suit the required door width.

In the area of a bottom slat, the continuous chain 16 is secured by a bracket 74 to the slatted shutter. According to Fig. 5, the connection of the chain to the slatted shutter is appropriately provided such that the tensile force applied during upward travel of the slatted shutter from the closed position to the open position is distributed completely within the plane of the door leaf, with the result that horizontally directed force components are avoided which would lead to a tilting moment in the slatted shutter, due to which transmitted forces would act on the guide tracks, thus pushing the guides apart, while the rollers would be subjected to elevated wear owing to the massive load.

The bracket 74 further exhibits, for example, a protruding, rigid end 76 which, in the open position of the door, meets a rubber stop 78, arranged at the top of the lintel, with virtually no .
nolse emlsslon.

According to Fig. 6, a weight balance 80 is provided to adapt the tensile force acting on the drive of the lift-type door to the prevailing weight of the freely suspended length of the slatted shutter, said weight balance 80 exhibiting a balance spring 82 Z4~ S'~r-3~3 and a belt 84 secured thereto consisting of extensively nonelastic and tension-resistant, strong material. The bottom end of the balance spring 82, which take~ the form of a coil spring, is firmly secured to the floor. The belt 84 is wound around a shaft 88 via a deflector roll 86, which shaft 88, for example, interacts, via the pulley 72 shown in Figs. 1 and 5, with the drive of the lift-type door such that, as the slatted shutter is raised, the belt 84 is unwound from the shaft 88 and the spring 82 is correspondingly relaxed, while when the slatted shutter is lowered, the belt 84 is wound onto the shaft 88 with a corresponding tensile force being exerted on the balance ~pring 82 90 that this is placed under tension.

The shaft 88 features a predetermined initial diameter, the value of which is selected su~h that, in relation to (i) the thickness of the belt 84, (ii) the length at rest b of the balance spring 82, (i~i) the strength of the balance spring 82, and (iv) the total weight of the slatted ~hutter corresponding to the door height, the required characteristic of the weight balance 80 can be determined.

For example, with a clear door height of 3 m, the prevailing cle~r height of the remaining door opening in ~lillimetres, has a value of "0 mm" representing the fully clo~ed door, and the valuo "3,000 m~" representing the completQly open door, the total force of weight GT of the freely su~pended slatted ~hutter acting on the door, and the spring power FF acting on the drive. The weight balance 80 is ad~usted such that, when the door is closed, the balance spring is extended 90 as to produce an excess spring power of approx. 260 N above the force of weight of the slatted shutter. ~his ensures that, when operating the closed door, the slatted shutter will also rise without additional drive actuation to 2~7~

approximately that height at which the force of weight of the freely suspended slatted shutter is in equilibrium with the corresponding spring power. This occurs at a height of approx. 1 m. As the door continues to move further upward, the prevailing force of weight at each point is virtually in equilibrium with the effective spring power so that the drive essentially only needs to overcome the prevailing frictional forces.

For reasons of space efficiency, one weight balance containing at least one balance spring is provided on each side of the lifttype door according to the invention.

Claims (2)

1. A lift-type door with 1.1 a slatted shutter (12) featuring a plurality of slots (14) which 1.1.1 are of rigid construction, 1.1.2 cover the width of the door opening (1), and 1.1.3 can be angled relative to one another; and 1.2 two guide tracks (2, 2') which 1.2.1 are arranged at the respective opposing sides (3, 3') of the door opening (1), 1.2.2 starting from a vertical section (4) running vertically approximately over the height of the door opening (1), 1.2.3 converge at the inlet (8) of the lift-type door into a helix-shaped, inwardly directed spiral section (10) in which the slatted shutter (12) in the open position of the lift-type door can be moved such that the plurality of slats (14) is stored in the heliz-shaped track without the slats coming into mutual contact.

2. A lift-type door as claimed in claim 1, wherein the spiral section (10) of the guide track (2, 2') features an extension section (82) which runs essentially horizontally and can be separately installed.3.A lift-type door as claimed in claim 1 or 2, wherein the guide tracks (2, 2') are provided in the form of a pair of round section rods (28,30).
4. A lift-type door as claimed in one of the preceding claims, characterized by a weight balance (80) for adapting the tensile force acting on the drive of the lift-type door to the prevailing weigth of the freely suspended length of the slatted shutter (12), wherein the weight balance (80) features.

a balance spring (82) which can be tensioned or compressed, and a belt (84) secured to the said balance spring (82), which belt (84) can be wound in approximately flush-overlapping layers on a shaft (88) which interacts with the drive of the lift-type door and exhibits a predetermined initial diameter.
5. A lift-type door as claimed in one of the preceding claims, characterized by a continuous chain (16) connected to the slatted shutter (12), which continuous chain (16) can be driven by an electric motor (18).
6. A lift-type door as claimed in one of the preceding claims, characterized by a sealing lip (52) horizontally arranged at the inlet (8) of the lift-type door and across approximately the entire door width, said sealing lip (52) protruding perpendicular to the door leaf plane up to the area of the guide tracks (2, 2').