Background of the Invention A typical traction elevator system includes a car and a counterweight disposed in a hoistway, a plurality of ropes that interconnect the car and counterweight, and a machine having a traction sheave engaged with the ropes.

The ropes, and thereby the car and counterweight, are driven by rotation of the traction sheave. The machine, and its associated electronic equipment, along with peripheral elevator components, such as a governor, are housed in a machineroom located above the hoistway.

A recent trend in the elevator industry is to eliminate the machineroom and locate the various elevator equipment and components in the hoistway. An example is JP 4-50297, which discloses the use of a machine located between the car travel space and a wall of the hoistway. Another example is U. S. Patent 5,429,211, which discloses the use of a machine located in the same position but having a motor with a disc-type rotor. This configuration makes use of the flatness of such a machine to minimize the space needed for the machine in the hoistway. This machine disclosed also makes use of permanent magnets in the rotor in order to improve the efficiency of the machine. These types of machines, however, are limited to relatively low duties and low speeds.

In practice, these types of elevators require an extension of the hoistway in order to fit the machine and other equipment. The extension may be accomplished either by extending the cross-sectional area of the hoistway to

accommodate the equipment or by extending the top of the hoistway upward and beyond the roof line of the building. Both of these configurations can add to the cost of installation of the elevator system. In addition, placing the machine and other typical machineroom equipment in the hoistway requires special procedures and precautions to be taken in order to service the equipment.

The above art notwithstanding, scientists and engineers under the direction of Applicants'Assignee are working to develop elevator systems that efficiently utilize the available space within a building.

Disclosure of the Invention According to one embodiment of the present invention, an elevator system includes a machineroom that is a self-contained unit that may be installed by placing the unit adjacent to the hoistway.

As a result of the machineroom being self-contained, the entire machineroom may be pre-assembled and tested at the factory prior to shipping to the building site. Once at the building site, the machineroom may be placed into position without further need to install the machineroom components, such as the machine, drive, controller, governor, etc. This feature saves in installation time and cost. In addition, once the machineroom is installed it may be used as a winch to install the hoistway equipment, such as the guide rails.

According to another embodiment of the present invention, an elevator system includes a machineroom that is disposed vertically adjacent to the hoistway and includes a height dimension such that the combination of the hoistway and machineroom fits below the roof line of the building.

According to a further aspect of this embodiment, the machineroom has a cross-sectional area substantially equal to the cross-sectional area of the hoistway.

As a result of its compact size, the machineroom may be installed within the same horizontal space as the hoistway and without the necessity to extend the size of the building. If the machineroom is mounted above the hoistway, it may

be fit into the building without exceeding the roof line of the building. This feature reduces the cost of the building construction and provides flexibility into the design of the building.

A principal feature of the present invention is the use of flat ropes. Flat rope, as used herein, is defined to include ropes having an aspect ratio, defined as the ratio of width w relative to thickness t, substantially greater than one. A more detailed description of an example of such ropes is included in commonly owned co-pending US Patent Applications Serial Number 09/031,108, entitled"Tension Member for an Elevator", filed February 26,1998, and Serial Number 09/218,990, entitled"Tension Member for an Elevator", filed December 22,1998 both of which are incorporated herein by reference.

The use of flat ropes results in a very compact machine that can be fit within the space constraints of a compact machineroom without adversely affecting the performance of the elevator system. This permits the machineroom to be sized such that it can be conveniently fit into the space between the hoistway and the boundaries of the building, such as the roof line. In addition, the compact size and lightweight of the machine and machineroom permits the machineroom to be assembled as a self-contained unit that is easily handled at the building site during installation of the elevator system.

The foregoing and other objects, features and advantages of the present invention become more apparent in light of the following detailed description of the exemplary embodiments thereof, as illustrated in the accompanying drawings.

Brief Description of the Drawings Figure 1 is an illustration of an elevator system according to the present invention.

Figures 2,3 and 4 are illustrations of an alternate embodiment of the elevator system. Figure 2 illustrates the installed elevator system ; Figure 3

illustrates the machineroom as a self-contained unit; and, Figure 4 illustrates the layout of the machineroom.

Figures 5 and 6 are illustrations of a further embodiment of the elevator system. Figure 5 illustrates the installed elevator system and Figure 6 illustrates the machineroom including sound isolation material.

Figure 7 is a sectional, side view of a traction sheave and a plurality of flat ropes, each having a plurality of cords.

Figure 8 is a sectional view of one of the flat ropes.

Best Mode for Carrying Out the Invention Illustrated in Figure 1 is an elevator system 12 having a car 14 and counterweight 16 interconnected by a plurality of ropes 18 for movement within a hoistway 20, and a machine 22 engaged with the ropes 18. The car 14 includes a pair of diverter sheaves 24 that engage the ropes 18 and the counterweight 16 also includes a diverter sheave 26 engaged with the ropes 18. The hoistway has a vertical height dimension"H"that is equivalent to the travel distance of the car, including any necessary safety and overrun distance.

The machine 22 is disposed within a compact machineroom 32 located above the hoistway 20 and includes a motor 28 and a traction sheave 30 engaged with the ropes 18. The machineroom 32 includes a floor 34, sidewalls 36 and an upper panel 38. The machineroom 32 has an internal height dimension"d", measured from the floor 34 to the upper panel 36, and a horizontal cross-sectional area that permits the machineroom 32 to fit within a space above the hoistway 20 and below the roof line 40 of the building. The floor panel 34 of the machineroom 32 supports the load of the machine 22 by engagement with the walls 42 of the hoistway 20 and further defines the ceiling 44 of the hoistway 20.

A principal feature of the present invention is the flatness of the ropes used in the above described elevator system. The increase in aspect ratio results in a rope that has an engagement surface, defined by the width dimension"w",

that is optimized to distribute the rope pressure. Therefore, the maximum rope pressure is minimized within the rope. In addition, by increasing the aspect ratio relative to a round rope, which has an aspect ratio equal to one, the thickness "tl"of the flat rope (see Figure 8) may be reduced while maintaining a constant cross-sectional area of the portions of the rope supporting the tension load in the rope.

As shown in Figure 7 and 8, each flat rope 722 includes a plurality of individual load carrying cords 726 encased within a common layer of coating 728.

The coating layer 728 separates the individual cords 726 and defines an engagement surface 730 for engaging the traction sheave 724. The load carrying cords 726 may be formed from a high-strength, lightweight non-metallic material, such as aramid fibers, or may be formed from a metallic material, such as thin, high-carbon steel fibers. It is desirable to maintain the thickness"d"of the cords 726 as small as possible in order to maximize the flexibility and minimize the stress in the cords 726. In addition, for cords formed from steel fibers, the fiber diameters should be less than. 25 millimeters in diameter and preferably in the range of about. 10 millimeters to. 20 millimeters in diameter. Steel fibers having such diameter improve the flexibility of the cords and the rope. By incorporating cords having the weight, strength, durability and, in particular, the flexibility characteristics of such materials into the flat ropes, the traction sheave diameter "D"may be reduced while maintaining the maximum rope pressure within acceptable limits.

The engagement surface 730 is in contact with a corresponding surface 750 of a traction sheave 724. The coating layer 728 is formed from a polyurethane material, preferably a thermoplastic urethane, that is extruded onto and through the plurality of cords 726 in such a manner that each of the individual cords 726 is restrained against longitudinal movement relative to the other cords 726. In addition, the coating layer is preferably flame retardant to minimize damage to the coating layer and cords in the event that the belt is exposed to

flames or damaging heat. Other materials may also be used for the coating layer if they are sufficient to meet the required functions of the coating layer: traction, wear, transmission of traction loads to the cords and resistance to environmental factors. It should be understood that although other materials may be used for the coating layer, if they do not meet or exceed the mechanical properties of a thermoplastic urethane, then the benefits resulting from the use of flat ropes may be reduced. With the thermoplastic urethane mechanical properties the traction sheave 724 diameter is reducible to 100 millimeters or less.

As a result of the configuration of the flat rope 722, the rope pressure may be distributed more uniformly throughout the rope 722. Because of the incorporation of a plurality of small cords 726 into the flat rope elastomer coating layer 728, the pressure on each cord 726 is significantly diminished over prior art ropes. Cord pressure is decreased at least as n~/2, with n being the number of parallel cords in the flat rope, for a given load and wire cross section. Therefore, the maximum rope pressure in the flat rope is significantly reduced as compared to a conventionally roped elevator having a similar load carrying capacity.

Furthermore, the effective rope diameter'd' (measured in the bending direction) is reduced for the equivalent load bearing capacity and smaller values for the sheave diameter'D" may be attained without a reduction in the D/d ratio. In addition, minimizing the diameter D of the sheave permits the use of less costly, more compact, high speed motors as the drive machine. For instance, in a standard 630 kg, 1 m/s elevator system with a traction sheave having a 100 mm diameter, a conventional cylindrically shaped machine may be used having a diameter of approximately 270 mm The traction sheave 724 having a traction surface 750 configured to receive the flat rope 722 is also shown in Figure 7. The engagement surface 750 is complementarily shaped to provide traction and to guide the engagement between the flat ropes 722 and the sheave 724. The traction sheave 724 includes a pair of rims 744 disposed on opposite sides of the sheave 724 and one or more

dividers 745 disposed between adjacent flat ropes. The traction sheave 724 also includes liners 742 received within the spaces between the rims 744 and dividers 745. The liners 742 define the engagement surface 750 such that there are lateral gaps 754 between the sides of the flat ropes 722 and the liners 742. The pair of rims 744 and dividers, in conjunction with the liners, perform the function of guiding the flat ropes 722 to prevent gross alignment problems in the event of slack rope conditions, etc. Although shown as including liners, it should be noted that a traction sheave without liners may be used.

The use of such flat ropes and the resulting compactness of the machine permits a very compact machineroom to be used. This machineroom may be fit within the cross-sectional area of the hoistway and have a height dimension, as measured from the floor to the upper panel, that is substantially the same, or only slightly larger, dimension as the height of the machine. For the 630 kg, 1 m/s elevator system described above, the height dimension of the machineroom may be approximately 275 mm. This permits the hoistway and the machineroom to be fit below the roof of the building, i. e., without the need to have a machineroom on the roof or an extended hoistway that extends beyond the roof line.

In addition to the use of flat ropes, the necessary overhead space in the hoistway for the car may be minimized by eliminating or limiting the need for mechanics to work from the roof of the car. Access to the machine may be accomplished by having an access panel in one of the side walls or by having an access panel in the upper panel of the machineroom. The access panel may be a hinged door, a sliding door or any other convenient type of opening. As an alternative, an access panel may be placed in the floor of the machineroom such that, if desired, a mechanic may get access to the machine from the top of the car.

Although disclosed in Figure 1 as having the machineroom 32 located vertically adjacent to and above the hoistway 20, it should be noted that the machineroom may also be placed vertically adjacent to but below the hoistway.

In this configuration, the compactness of the machine and machineroom may

permit the pit equipment, e. g., buffers for the car and counterweight, to be integrated around or into the machineroom, thereby minimizing the space requirements of the elevator system.

Illustrated in Figures 2,3 and 4 is an alternative embodiment of the present invention. In this embodiment, the elevator system 50 has a machineroom 52 including a machine 54 and various other equipment, such as an electric drive unit 56 for the machine 54, an electronic controller 58 for the elevator system 50, and a governor 60. The machineroom 52 is a self-contained unit such that all of the machineroom equipment is enclosed within a container 62 that may be pre- assembled and shipped to the building site. In addition to the above equipment, a cooling fan 64 may be integrated into the machineroom unit 52 to cool the electronic equipment in the machineroom 52. As a result of the compact size of the machineroom 52, a single fan may be used to provide cooling for all of the machineroom equipment, rather than having a separate fan for each electronic unit, as is conventional.

The container includes a floor 66, sidewalls 68, an upper panel 70, and a cut-out or recess 72 on each side. The cut-outs 72 are sized and located to engage a pair of beams 74 disposed within the hoistway 76. The beams 74, which may be supported by the walls 78 of the hoistway or by the guiderais (not shown) of the elevator car 80 and/or counterweight 82, support the load of the machineroom 52 once it is placed above the hoistway 76.

As a self-contained unit, the machineroom 52 and all of the equipment in the machineroom may be assembled at a factory or any other location remote from the building site. As such, each piece of equipment may be precisely located prior to shipping the machineroom unit 52 and, once at the site, the machineroom unit 52 only needs to be placed above the hoistway76, and therefor installation time and cost for the elevator system 50 is reduced. The machine 54 may then be used as a winch to lift other hoistway equipment, such as guide rails for the car 80 and counterweight 82, into position within the hoistway 76 during construction.

This feature eliminates the need for a separate winch to construct the elevator system.

In some instances it may be desirable to take advantage of the benefits of the self-contained machineroom without the need to avoid exceeding the roof line of the building. An example may be a high rise building in which the benefits if having no machineroom above the roof line are minimal. Figures 5 and 6 illustrate an elevator system 100 that takes advantage of the convenience and ease of assembly of the self-contained machineroom by placing the machineroom unit 102 on the roof 104 of the building. In this embodiment, the machineroom 102 is supported by a pair of beams 106 that are integrated into the roof 104 of the building, rather than in the hoistway as shown in the embodiment of Figures 2-4.

This elevators system takes advantage of the lower cost installation and ease of assembly of the present invention.

In addition, this embodiment shows the use of sound insulating material 108 that may be added to the machineroom unit 102 to reduce noise emissions. It should be noted that such sound insulating material may also be applied to the previous embodiments shown in Figures 1-4.

Although the invention has been shown and described with respect to exemplary embodiments thereof, it should be understood by those skilled in the art that various changes, omissions, and additions may be made thereto, without departing from the spirit and scope of the invention. For instance, the car and counterweight may be directly roped rather than using the 2: 1 roping as illustrated. In this configuration, the diverter sheaves on the car and counterweight could be eliminated.