DOOR

Abstract: A door, particularly for industrial use, comprising a door leaf (11) which is suspended at the upper edge of a doorway and which is raised by line hoisting means (19-22) which are connected to a hoisting device (24, 26) powered by a motor (25). The door leaf comprises one or more pieces of a flexible material (17) in one or more layers, which are attached to a plurality of lateral braces (13-16) arranged one above the other. The lateral braces are guided at each of the ends in a vertical guiding profile (12) at each side of the door. The hoisting means (19-22) are connected to the lateral braces (13-16) by guiding over a number of pulleys (27) arranged on the lateral braces (13), to impose equal distance of movement for the pulling means of the different lateral braces. To increase the raising and lowering velocity, a counterweight (31, 32) is arranged on each side of the door for balancing of a part of the weight of the door leaf, a pulling line (29, 30) for each counterweight is connected to the hoisting device (24, 26) over a pulley (33, 34) at the upper edge of the door, and the pulling lines from the counterweights (31, 32) being connected to the hoisting drum (24) of the hoisting device.

Description: DOOR The invention relates to a door, particularly for industrial purposes, as stated in the introduction to Claim 1. Background From US-Patent Specification No. 5,301,732 a door of this kind is known. It operates by raising and lowering doors up to a certain velocity and size. The development has however created the need for fast raising and lowering also for large doors, i.e. doors of 5 meters or higher. Danish Patent Specification No. 127.859 provides a telescopic door of rigid panels with counterweights balancing a part ofthe door weight. Prior art for a non-powered door uses hoisting drums at the upper edge for raising lines extending down to the various panels. On the shaft ofthe hoisting drums is also an extra line connected to a counterweight, to provide for raising ofthe door with the hoisting drums. This separated arrangement ofthe power input and power output demands relatively large space and a heavy transmission axle. The problem of high speed operation is not only related to raising ofthe door leaf, but also to its lowering. With door leafs made extremely light for material saving reasons sufficient lowering force in relation to friction and inertia may be difficult to gain for high speed operation. Objects The main object ofthe invention is to provide a door based on the technology of US-Patent Specification No. 5,301,732 which is lightweight, can stand high wind loads, and which can be raised and lowered faster than doors found in the prior art. It is desirable to create a door which may be raised manually during power failure or other deficiencies in normal raising (emergency opening). Furthermore, a plain fabric door without pleats, is desirable. It is also an object ofthe invention to provide a door with a powered lowering. More particularly, it is an object ofthe invention to provide a door with a certain lift on the individual door sections, to reduce the raising force relatively to prior art doors. A particular object is to provide a door according to the introductory part of claim 1, which has a reduced lowering time, to be able to close, i.e. lower the door, as fast as it can be opened, i.e. raised. A still further object ofthe invention is to provide a door which may also be used in inclined walls and horizontal ceilings. The invention The basic features ofthe invention is described in claim 1, the characterizing clause stating the novel features. Test and experiments have shown that even the largest doors which have been built, can have lowering and raising speeds of 0,6 m/sec. The arrangement ofthe invention , provides a particularly advantageous power transfer with a simple attachment to the hoisting equipment. The balancing ofthe weights in the components removes the need for complicated and expensive safety equipment. Prior art safety equipment has included centrifugal brakes which engage when exceeding a predetermined rotational speed at lowering, or spring loaded clamping arrangements which engage the lower beam when a hoist line breaks. In claims 2-10 further advantageous features are stated. Details of these features and their function will appear from the examples described below. By providing a downward load on closed doors, the fabric will always stay plain, without flapping and making pleats. For safety reasons, industrial doors should have a reversing function, in case an object is introduced to the closing door The present invention will increase the safety in this function by having the door balanced, which will enable faster reversing than for doors found in the prior art. Example The invention will be described in more detail with reference to the drawings, wherein Fig. 1 shows a schematical front view of an embodiment ofthe invention, with two counter weights, Fig. 2 shows a corresponding plan view ofthe door in Fig. 1, and Fig. 3 shows a side view ofthe hoist drum. Figure 1 shows a fabric door with a door leaf 1 1 which may be prepared according to US-Patent Specification No. 5,301,732, engaging a guide profile 12 on each side ofthe doorway. The door leaf 1 1 comprises in this embodiment four horizontal beams or lateral braces 13, 14, 15, 16, seen from the bottom and upwards. The lateral braces 13-16 are provided with rollers (not illustrated) fitted at each end, that are coupled with equivalent grooves in the guide profile 12. On the external side ofthe lateral braces 13-16 a fabric 17 is attached in an appropriate manner, that can either be one continous sheet or joined pieces for each lateral brace. In an equivalent manner the door leaf 1 1 is covered on the internal side by a second layer fabric 17, to create a layer of air between the two fabric sheets, which can improve the thermal insulation ofthe door. The lateral braces 13-16 can be designed as appropriate They can be, but not restricted to, lattice braces, struts or other forms of support, made of light weigth materials, steel or composites. Separate hoisting lines or hoisting belts 19-22 provided for each lateral brace 13-16 respectively, are used to raise the individual lateral brace 13-16 Each hoist line 19 for the lowermost lateral brace is guided over a pulley 23 located at the upper edge ofthe doorway and from there it extends to a line or hoisting drum 24 arranged centrally at the upper edge ofthe doorway and with power transmission from an electric motor 25 (Fig. 2) over a bevelled gear 26. The hoisting line 20 for the second lowermost lateral brace is guided from a pulley 27 at the second lowest lateral brace 14 and upward to an attachment point at the next higher lateral brace 15. In this way, a transmission which is raising both lateral braces 13 and 14 to the upper edge ofthe doorway by the hoisting ofthe hoisting lines 19, 20 is achieved. Correspondingly the hoisting lines 21 and 22 ofthe two upper lateral braces 15 and 16 guided over an increasing number pulleys to reduce the raising distance. The hoisting lines or belts can also be attached to one another or to a certain number of lateral braces, depending on the height ofthe door and the total number of sections. As may be seen from Fig. 2 and 3, the hoisting drum 24 is divided into several chambers with inteφosed flanches 28, but with a common core diameter. Centrally on the hoisting drum 24 space is arranged for hoisting lines or hoisting belts 29, 30 from two counterweigths 31 and 32, e.g. of metal, arranged on each side ofthe door, on the outer side ofthe guide profile 12. The arrangement ofthe door demands space for accomodating the counterweights 31, 32 on the side ofthe guide profile Each hoisting line 29 and 30 is guided over a pulley 33 and 34 respectively, at the upper end of each guide profile 12 and into a section 35 ofthe hoisting drum 24. By placing the section 35 centrally, the momentum ofthe two hoisting lines relative to the journalling ofthe hoisting drum 24 is balanced. From the lowermost side of each counterweight 31, 32, a tensioned line 36, 37 " extends down to pulleys 38, 39 and from there on to attachment points 40, 41 at the lower side of the lowermost lateral brace 13 The pulling lines 36, 37 are resiliently attached at the lower side of the counterweights 31, 32. The counterweights may be 50% ofthe weight ofthe movable parts ofthe door, depending on the transmission ratio ofthe hoisting lines 19-22 The door leaf will then be in balance with the counterweight in its central position. This will make a favourable base for increasing the speed ofthe movement ofthe door leaf. The invention will allow a raising and lowering velocity of approximately 0,6 m/sec even for the largest doors now being built. These balancing characteristic remove the need for complicated and expensive safety equipment for stopping a sudden door drop. On prior art doors this may be centrifugal brakes which engage if the rotational speed exceeds a predetermined rate at lowering, or a springloaded clamping arrangement which engages the lowermost lateral brace at hoisting belt failure. The speed ofthe door closing may be restricted if underpressure arises between the fabrics. The use of downward pull as shown in the example is a favourable further development of the invention. This will allow large reduction in the door's mass, making the movable mass on raising and lowering ofthe door low and thus makes it a quick operation. Even an extremely light door will still have the necessary closing force The invention provides a substantial improvement the "high speed door" area. It also means that it is now possible to manufacture large high speed operation doors which will withstand substantial wind pressure. The use ofthe downward pulling arrangement will be particularly advantagous when the door according to the invention is opened or closed under high wind pressure. In such cases the wind pressure may create a braking effect against the guiding profiles 12. Fo ced opening will then be necessary. The hoist drum 24 may be arranged in a carrying beam or a motor mounting beam 42 which is pre-manufactured with the pulleys and fastening elements for the motor 25 and which is adapted to be mounted at the upper end ofthe guiding profiles 12. The motor mounting beam 42 may be a lattice girder beam. It enables the substantial reduction ofthe installing time of a door. When the motor mounting beam 42 is provided as a part ofthe building structure, the hoisting equipment and the counterweights can easily be mounted with screw bolts, (not illustrated). The lines in the above example, e.g. in the form of a steel wire, may be replaced with belts, e.g. of polyester or polyamide. With equal diameter on all parts ofthe hoist drum 24, the line forces may be balanced with the door leaf in its central position, i.e. with all sections ofthe winch drum half filled and the equal arm of force. A balanced door may therefore be opened or closed to central position when it is released from an end position without application of external power. This is a favourable base for applying a motor for forced closing or opening. By providing the hoisting lines 19-23 from the lateral braces, and the pulling lines 29, 30 from the counterweights 31, 32 with different diameters or gauge, it is possible to change the balance point ofthe door leaf. By providing the hoisting lines or belts 29, 30 for the counterweights 31, 32 with higher gauge than the belts from the door section, it is possible to have the door to open or to close automatically when the motor brake is released. This may occur at a power supply failure. Corresponding results can be obtained by providing different winding diameters for the hoisting lines and counterweight lines respectively in the hoist drum. It may also be provided by increasing the size ofthe counterweights, to increase the impact ofthe counterweights to substantially more than 50% ofthe momentum ofthe door, as stated above. In an alternative embodiment the hoisting lines 19 are guided over pulleys on the lowermost lateral brace and upward to an attachment in the second lateral brace, corresponding to the teaching of US-Patent Specification No. 5,301,732.

Claims: AMENDED CLAIMS [received by the International Bureau on 03 April 1997 (03.04.97); original claim 10 cancelled; original claim 6 amended; remaining claims unchanged (2 pages)] 1. Door, particularly for industrial use, comprising (A) a door leaf (1 1) which is suspended at the upper edge of a doorway and which is raised with line or belt hoisting means (19-22) which are connected to a hoisting device (24- 26) with a powered hoist, (B) the door leaf comprises one or more pieces of a flexible material (17) in one or more layers, which are attached to a plurality of lateral braces (13-16) arranged one above the other, and wherein (C) the lateral braces are guided at each of its ends in a vertical guiding profile (12) at each side ofthe door, and that (D) the hoisting means (19-22) are connected to the lateral braces (13-16) by guiding over a number of pulleys (27) arranged on the lateral braces (13-16), to impose equal distance of movement for the pulling means ofthe different lateral braces, characterized in that (E) a counterweight (31, 32) is arranged on one or each end ofthe door for balancing of a part ofthe weight ofthe door leaf in a manner known per se, (F) that a pulling line or belt (29, 30) for the counterweight or for each ofthe counterweights is connected to the hoisting device (24, 26) over a pulley (33, 34) at the upper edge ofthe door, and (G) that the pulling line or belt from the counterweight or from each ofthe counterweights (31, 32) is connected to the hoisting drum (24) ofthe hoisting device. 2. Door according to claim 1 , characterized in that the hoisting drum (24) has a centrally arranged section (35) for the pulling line or for each pulling line from the counterweights (31, 32). 3. Door according to claim 2, characterized in that the pulling lines (19-22) ofthe door leaf are distributed on sections of the hoisting drum being symmetrical to the central section (35) ofthe hoisting drum 4. Door according to anyone of claims 1-3, characterized in that the total counterweight provides a momentum which corresponds to at least 50% ofthe momentum created by the door leaf. 5. Door according to claim 4, characterized in that the momentum ofthe counterweights is substantially larger than the momentum ofthe door leaf. 6. Door according to anyone of claims 1-4, characterized in that a line (36, 37) is connected to the counterweight or to each ofthe counterweights (31, 32) or to the hoisting drum and is guided over a pulley (38, 39) arranged at the lower end ofthe guiding profiles (12), and being resiliently attached under the lowermost lateral brace (13). 7. Door according to claim 6, characterized in that the lines or belts (19, 23) from the lateral braces, and the pulling line or lines (29, 30) from the counterweight or counterweights has/have different gauges, to enable automatic closing or opening in case of an emergency situation like current failure or similar. 8. Door according to anyone of claims 1-7, characterized in that the guiding profiles (12) are extended upward to the upper edge ofthe doorway, to carry a lattice girder beam (42) for the hoisting drum (24) and the operating motor (25, 26), pulleys (33, 34) for the pulling line or pulling lines (29, 30) from the one or more counterweights (31, 32) being arranged at the upper level ofthe beam. 9. Door according to anyone of claims 1-8, characterized in that the hoisting drum for the pulling line(s) from the counterweight(s) has a larger diameter, than the hoisting drum for the remaining hoisting lines or belts.

Inventors: AABEL LASSE, AABEL, LASSE
Applicants: AABEL LASSE, NOMAFA AB, AABEL, LASSE
Application year: 1996
Main classification: E06B9
IPC codes: E05D15, E06B9