AU748085B2 - Slatted door - Google Patents

Description

WO 99/61742 PCT/AU99/00398 -1- SLATTED DOOR The present invention relates to doors and in particular to slatted doors suitable for use in an industrial application. Doors of this kind are sometimes known as 'high speed doors'.

The door of the present application is suitable for an opening such as an entrance to a garage, warehouse or the like. The door includes a plurality of slats or panels which are moveable between a closed position and an open position of the door. In the closed position of the door, the slats or panels abut side by side to substantially cover the opening. In the open position of the door, the slats or panels are repositioned in a face to face relationship to substantially uncover the opening.

Doors of the above kind are broadly known, inter alia, from AU Patent Specification 235268 to K-M Steel Products Pty. Ltd. However, a disadvantage of the door disclosed in this reference is that it is not suitable in an environment in which the door is subjected to relatively high wind pressure such as may be experienced in a hurricane or cyclone. Slatted doors are inherently unstable under such conditions.

In a prior art roller-shutter arrangement, a curtain comprising a plurality of slats, is wound up by means of a drum under high pressure. This can cause damage to exposed surfaces when the curtain is operated. To withstand high wind pressure, shutters of this kind require wind locks on the end of the curtain.

However, the wind locks come into effect even under conditions of minor wind.

After the wind locks are engaged on stops inside tracks associated with the curtain, friction can prevent the curtain from moving in a vertical direction. In this case the door can't be operated. Another disadvantage of roller shutters is a disturbing noise level associated with opening and closing of the shutters and a relatively low maximum operating speed.

An object of the present invention is to alleviate the disadvantages of the prior art or to at least provide the public with a choice.

2 According to the present invention there is provided a door for an opening, said door including a plurality of slats moveable between a closed position in which said slats abut side by side to substantially cover the opening and an open position in which said slats are arranged face to face to substantially uncover the opening, said door including: means including a plurality of pantographs for guiding said slats between said open and closed positions; means associated with said guiding means for biasing said slats towards said closed position; and means for counterbalancing moving parts including said slats of said door.

The pantographs may be arranged to pivot between a first position associated with the open position of the door, and a second position associated with the closed position of the door, when the biasing means is fully biasing the 15 slats. The guiding means may include means for attaching the pantographs to at least one slat so that when the pantographs pivot between the first and second positions, the slat moves between its open and closed positions.

Preferably, the attaching means includes the biasing means.

The biasing means may include a torsion bar. The biasing means may 20 be actuated when the slats first abut each other. The biasing means may fully bias the slats when the pantographs are in the second position.

Where the biasing means includes a torsion bar, one end of the torsion bar may be attached to a pivot axis associated with the pantographs and the other end of the torsion bar may be attached to a slat. The other end of the torsion bar preferably is attached to the slat at a position that is spaced inwardly from one end of the slat. The position of attachment may be spaced inwardly approximately 25% of the length of the slat.

The door may include means for driving the guiding means between the open and closed positions. The driving means may be an electric, pneumatic or hydraulic motor- gear unit.

W:\marie\GABNODEL\40243-99.doc WO 99/61742 PCT/AU99/00398 -3- To facilitate understanding of the present invention, preferred embodiments of the invention will now be described with reference to the accompanying drawings wherein: FIG. 1 is a sectional front view along I-I in FIG. 2 showing an example of a slatted door according to the invention in a closed position in which parts of the covers and a guide element on the left-hand side thereof are removed; FIG. 2 shows a sectional view along II-II in FIG. 1; FIG. 3 shows a sectional view along III-III in FIG. 1; FIG. 4 shows a sectional view along IV-IV in FIG. 1; FIG. 5 is an enlarged sectional front view of the headroom area of the lefthand frame taken along V-V in FIG. 6; FIG. 6 shows a sectional view along VI-VI in FIG. 5 in which front covers and end seals are omitted for reasons of clarity; FIG. 7 is a sectional side view along VII-VII in FIG. 8 showing the headroom area in an open-door position in which end seals are not shown for reasons of clarity; FIG. 8 is a sectional top view along VIII-VIII in FIG. 7 when door is open, and shows the left-hand frame with covers installed; FIG. 9 is a partially cut away, right side view of FIG. 10 in a closed-door position, and without panels for reasons of clarity; FIG. 10 is a sectional left side view along X-X in FIG. 9; FIG. 11 is a partially cut away view of the head- room area and shows end seals and panels in an open door position; FIG. 12 shows an alternative assembly to FIG. 8; FIG. 13 shows one form of means for connecting the transmission elements to panels; FIG. 14 shows a sectional view along XIV-XIV in FIG. 15, of the preferred connection between transmission elements and panels; FIG. 15 shows a partially view of FIG. 14; FIG. 16 shows the principle of an alternative counterbalance assembly; FIG. 17 is an alternative embodiment to FIG. 7 and shows reinforced panels in an open door position; WO 99/61742 PCT/AU99/00398 -4- FIG. 18 shows the reinforced panels of FIG. 17 in a closed-door position; FIG. 19 shows another embodiment of reinforced panels in a closed-door position; and FIG. 20 shows the panels of FIG. 19 in an open-door position.

Referring to FIGS. 1-4, it may be seen that the slatted door assembly 1 basically comprises a plurality of movable slats or panels 2, a synchronising and guiding mechanism 3 at each end of the panels 2, a counterbalance assembly 4 preferably acting on each synchronising and guiding mechanism 3, a pair of symmetrical self supporting frame assemblies 5, and a drive assembly 6.

FIGS. 5-6 show one form of synchronising and guiding mechanism 3 in conjunction with the panels 2.

The synchronising and guiding mechanism 3 includes a plurality of pantographs 8 wherein one center shaft 9 located at the end of the pantograph assembly 8 pivots in a self-aligning bearing 10. The synchronizing and guiding mechanism 3 further includes center shafts 13-14, torsion members 11, at least one rotatable rope guide 35, and a support roller 21 installed on each, or preferably each second, center shaft of pantographs 8. In another embodiment support rollers 21 may be replaced with sliding pads.

To determine the direction of rotation of the support rollers, another embodiment of the invention, shown in FIG 12, comprises a support roller 22 and a support roller 23, installed on each center shaft 14 of pantographs 8.

Like the center shafts 13 and 14, center shaft 9 is fixed to a torsion member 11. Each torsion member 11 includes an elongate element. The elongate element may be solid or hollow such as tubular. It is possible to replace the combination of the torsion member 11 and center shaft by a single element.

Each torsion member 11 is connected to a pivot axis associated with one lever 12 of pantograph 8. This connection can be form-fitting or can be achieved by welding, for example.

To facilitate installation at the building site, all parts of the synchronising and guiding mechanism 3 may be pre-assembled.

WO 99/61742 PCT/AU99/00398 It may be seen in FIG. 4 and FIGS. 5-6 that intermediate panels 7, top panel 15 and bottom panel 16 inclusive, have inserted therein torsion members 11, which transmit a desired rotation to all panels. The torsion member 11 also transmits synchronised movement in a vertical direction, to all panels except top panel 15 which rotates only.

Alternative ways of connecting torsion members 11 and panels 7, 15 and 16 are shown in FIG. 13 and in FIGS. 14-15.

FIG. 13 shows torsion member 11 connected to a panel 7 by means of a spring pin 70. This has the advantage that after the torsion members 11 are inserted in all panels 7, 15 and 16, the required holes can be drilled in an open door position and no accurate tolerances are required for connecting torsion members 11 and levers 12 of pantographs 8.

The preferred version shown in FIGS. 14-15 includes a driving lug 18 fitted to each end of a torsion member 11 for transmitting torque to a driving slot 19 associated with a panel. An advantage of this connection is that it can' t be seen, and installation on the building site is less time consuming.

The driving lug 18 is placed a distance DI (refer Fig. 15) in from the end 17 of a panel, to allow the torsion member 11 to twist and behave like a torsion spring. The distance DI is related to the length of the torsion member and is determined by reference to the elasticity of the torsion member, the bias or preload tension to be applied to the panels and the angular displacement required of the torsion member. These calculations are well within the capability of the skilled addressee and are therefore not provided herein. In practice, the point of attachment of the torsion member and/or the length of the torsion member may be chosen so that flexing of the panels is minimized. Where a pair of torsion members is applied to each panel, they may be attached at points spaced inwardly approximately 25% from the ends of a panel. This may provide a substantially uniform distribution of preload tension to each panel in a closeddoor position. The flexible nature of the torsion members 11 may also perform a safety role, because, in the event that a human hand or other body part is accidentally caught between two adjacent panels preventing them from closing completely, the driving force may be taken up by an increase in preload tension WO 99/61742 PCT/AU99/00398 -6and may not cause permanent injury. Also, if the door is accidentally closed at too high a speed, damage to the door may be avoided because the torsion members 11 can twist and absorb energy.

As shown in FIG. 1, FIG. 4 and FIG. 7, there is installed between top panel 15 and bottom panel 16 a number of similar intermediate panels 7. To prevent exchange of air in a horizontal direction, panel 15 and intermediate panels 7 are fitted with seals 24. Panel 15 is packed by seal 67 which is fitted to top-plate 40. A channel 25 is inserted in bottom panel 16. Channel 25 receives a lower seal 26 equipped with integrated safety components. Lower seal 26 is commonly called a safety edge and is available in different forms as a standard product for high speed doors. Top panel 15 and bottom panel 16 may be formed without special tools, by re-machining intermediate panels 7.

The panels may be made from extruded aluminium or from preformed steel. To reduce inertia of the panels, they may be formed from composite materials and may contain reinforcing fibers such as carbon or glass.

As shown in FIG. 5 and FIGs. 9-10, to seal the ends of panels 7 and 16 in a vertical direction and to compensate for changes in their length, the panels are fitted with elastic end seals 27. The end seals 27 are slightly thicker than the panels 7 and 15-16, so that they abut each other in an open-door position to provide a gap 28 between panels 7,15-16. The gap 28 should be sufficient to prevent contact damage between the panels. Each end seal 27 preferably comprises a layer 29 with good sliding properties such as Teflon, a compressible and elastic core 30, which can be made of Polystyrene foam or an equivalent material, and an outer layer with lugs 31 for insertion into the panels.

In another embodiment end seal 27 may be formed from a single hollow and soft PVC material laminated with a low-friction coating.

For extra wide door-openings and extreme wind pressure, a reinforced version is shown in FIGS. 17-18. In this embodiment each panel 32 is reinforced with an extended rib section 33. This arrangement increases rigidity of the panels without the need for additional headroom. A gap 28 is also provided around the whole section of panel 32.

WO 99/61742 PCT/AU99/00398 -7- Where good insulation and loss of air are not of high priority but extreme wind pressure has to be withstood, an inexpensive version of a single-walled panel 34 with high corrugation and therefore high rigidity is shown in FIGS. 19- A reinforced version of panels is possible without an extended rib section 33 by doubling the height of the panels and connecting them to every second center shaft of pantograph 8 (ie. leaving out each second panel). This allows the thickness of the panels to be doubled and consequently increases rigidity of the panels without requiring additional headroom.

A cost-effective application of a counterbalance assembly 4 is shown in FIGS. 1-3 and FIGS. 5-6. Rope 36 supports center shaft 14 by means of ropeguide 35. Rope guide 35 is preferably located as close as possible to the center shaft 14 of bottom panel 16 or to center-shaft 14 of bottom-panel 16 itself. Two spaced pulleys 37 guide rope 36. The ends of rope 36 are connected to counterweight 38. To transmit positive and negative (ie. up and down) dynamic drive forces Fd from the drive assembly 6, the ends of a synchronizing or timing belt 39 in each frame assembly 5, are connected to the center of mass of counterweight 38. In some embodiments synchronizing or timing belt 39 may be replaced by an equivalent means such as a chain. Alternatively, dynamic drive forces Fd, can be transmitted to the center of mass of counterweight 38 by a pneumatic or hydraulic cylinder.

Thus rope 36 may be used not only to transmit a counterbalance force Fc but also to transmit positive and negative dynamic drive forces Fd to center shaft 14.

In a heavy duty version of the door, rope 36 may be arranged to support a second center shaft 14 to reduce stress in the components of the synchronising and guiding mechanism 3.

If a more dynamic application is desired, the kinetic energy of counterweight 38 may be reduced to 50% as shown in FIG. 16. To get the required force Fc in rope 36, the mass of the counterweight 38 can be doubled, to reduce its speed by 50%. As will be clear to those skilled in the art this WO 99/61742 PCT/AU99/00398 -8arrangement may reduce the kinetic energy of the moving mass by a factor of two.

Where high dynamic properties are essential, counterweight 38 may be replaced with a spring balance system, to provide a constant counterbalance force Fc. A constant counterbalance force can be provided by means of constant force springs made from flat spring steel, or as known in various door applications, by a combination of a torsion spring and a tapered drum.

In an alternative embodiment of the present invention the counterbalance system may be dispensed with altogether. Instead, the synchronizing or timing belt of the drive assembly may drive a center shaft 14 directly. Preferably the synchronizing or timing belt is adapted to drive the center shaft 14 of bottom rail 16. If for any reason the counterbalance assembly fails, the door panels will not drop because the synchronizing or timing belt or its equivalent may take up the weight of the unbalanced door weight, thus providing a safety feature.

Referring to FIG. 3 and FIG. 8 each self-supporting frame assembly includes a top plate 40 and a bottom plate 41, connected to vertical members 42 and 43. Frame assembly 5 includes mountings 48, 49 and 50 for pulleys. Frame assembly 5 also includes self-aligning bearing 10 connected as shown to top plate 40, and mountings 49 connected to bottom plate 41. The vertical members 42 and 43 are designed to take all dynamic and static forces, due to counterweight 38, the weight of the panels 2 and the weight of the synchronising and guiding mechanism 3. Furthermore, the frame assembly 5 includes removable covers 44 and 45 for easy access, a removable and adjustable guidecover 46 and a removable guide 47.

In the alternative embodiment of the present invention shown in FIG.12, vertical members 51 and 52 of the self-supporting frame assembly 5 can withstand all forces. To gain easy access for maintenance, vertical member guide member 53 and guide member 54 made of two hollow sections as shown, or as a single part, can be removed, following removal of covers 56, 57 and 58.

To allow a predetermined direction of rotation, support roller 22 applies a force to the runway of guide member 53 only, because gap 60 prevents contact with the runway of guide member 54. Also, because of gap 59, support roller 23 WO 99/61742 PCT/AU99/00398 -9applies a force to the runway of guide member 54 only. An advantage of this version includes less wear of the support rollers and more accurate guidance of center-shafts 14 without requiring any clearance. It also has an advantage of smoother operation and less noise from a closed-door position under windy conditions.

As shown in FIGS. 1,2 and 3, the preferred embodiment of drive assembly 6 includes in each self-supporting frame 5, a synchronizing or timing (idling) pulley 61 for synchronizing or timing belt 39 journalled for rotation on mountings 49, and a timing pulley 62 for timing belts 39 and 63, journalled for rotation on mountings 49. Drive assembly 6 further includes a motor-gear unit which can be installed to the left or right of self-supporting frame 5, and synchronizing pulleys 68 fixed to shaft 64. Shaft 64 is rotatably mounted in at least two self-aligning bearings 66. The preferred version of the motor-gear unit is electric and with power being supplied by a soft-starter such as a frequency converter. Alternatively, the apparatus may be powered by a pneumatic or hydraulic motor-gear unit or pneumatic cylinders. The motor-gear unit preferably is equipped with a releasable brake.

Finally, it is to be understood that various alterations, modifications and/or additions may be introduced into the constructions and arrangements of parts previously described without departing from the spirit or ambit of the invention.

Claims (14)

1. A door for an opening, said door including a plurality of slats moveable between a closed position in which said slats abut side by side to substantially cover the opening and an open position in which said slats are arranged face to face to substantially uncover the opening, said door including: means including a plurality of pantographs for guiding said slats between said open and closed positions; means associated with said guiding means for biasing said slats towards said closed position; and means for counterbalancing moving parts including said slats of said door.

2. A door according to claim 1 wherein said biasing means includes a S 15 torsion member.

3. A door according to claim 1 or 2 wherein said pantographs include levers arranged to pivot between a first position associated with said open position, :and a second position associated with said closed position when said biasing 20 means is fully biasing said slats.

4. A door according to claim 3 wherein said biasing means is actuated 0 intermediate said first and said second positions of said levers.

5. A door according to claim 3 or 4 wherein said biasing means is actuated when said slats first abut each other, said biasing means being arranged to fully bias said slats when said levers are in said second position.

6. A door according to claim 1 wherein said pantographs are arranged to pivot between a first position associated with said open position, and a second position associated with said closed position when said biasing means is fully biasing said slats, and means for attaching said pantographs to at least one slat Ssuch that when said pantographs pivot between said first and second positions, Ssaid slat moves between its open and closed positions. W:Aare\GABNODEL\40243-99.doc 11

7. A door according to claim 6 wherein said attaching means includes said biasing means.

8. A door according to claim 7 wherein said biasing means includes a torsion member, one end of said torsion member being attached to a pivot axis associated with said pantographs and the other end of said torsion member being attached to one said at least one slat.

9. A door according to claim 8 wherein said other end of said torsion member is attached to said one slat at a position that is spaced inwardly from one end of said one slat.

A door according to claim 9 wherein the position of attachment is spaced o•O 15 inwardly approximately 25% of the length of said one slat. .I o

11. A door according to any one of the preceding claims wherein said counterbalancing means includes a counterweight arranged to move in a :'.:direction that is opposite to the direction of movement of said slats.

12. A door according to any one of the preceding claims including means for driving said guiding means between said open and closed positions.

13. A door according to claim 12 wherein said driving means incudes an electric motor-gear unit.

14. A door substantially as herein described with reference to the accompanying drawings. DATED: 19 March, 2002 PHILLIPS ORMONDE FITZPATRICK Attorneys for: FRANCIS LEWIS JOHN CASSAR W:marde\GABNODEL4O243-99.doc