An important aim in elevator development work has been to achieve efficient and economical utilization of building space. In prior-art elevator solutions pro- vided with a machine room or a corresponding space, the placement of the hoisting machine and the space required by it limit the freedom of choice in elevator lay-out solutions. Additional space is required for the arrangements for rope passage between the machine room and the elevator shaft. The size and weight of especially a machine designed for larger loads, higher speeds and/or greater hoisting heights are a problem in respect of installation because it is not always possible to place the machine and the diverting pul- leys in the required positions due to insufficient space.

Specification WO 99/43589 discloses an elevator sus- pended using flat belts wherein relatively small belt bending diameters on the drive sheave and diverting pulleys are achieved. Problems with this solution, however, are a limited lay-out solution, placement of components in the elevator shaft and alignment of the diverting pulleys. Moreover, the alignment of the polyurethane-coated belts used, which have a load- bearing steel component inside them, is problematic e. g. in a situation where the car is tilted. In an elevator implemented in this manner, at least the ma- chine and/or the structures on which it is secured in place must be fairly massive to avoid undesirable vi-

brations. Also, the massive construction of the rest of the elevator structure required to maintain the mu- tual alignment of the diverting pulleys and the trac- tion sheave increases the weight and cost of the ele- vator. In addition, the installation and adjustments of such a system are difficult tasks requiring great precision.

In connection with modernization of an elevator it is possible to alter the suspension of the elevator by replacing an earlier 1: 1 or 2: 1 suspension arrangement with an arrangement with a suspension ratio of 4: 1 or even greater. This makes it possible to use a hoisting machine and diverting pulleys of a smaller size, which will be easier to place in appropriate positions in respect of elevator layout. In the case of elevators with machine room, however, there is the problem that the number of holes through the bottom of the machine room has to be increased to allow all the new rope passages needed in 4: 1 suspension to be implemented.

However, making new holes in the bottom of the machine room is expensive and hazardous because there may be reinforcement bars or the like in the bottom structure just where a new hole should be made. In previously known solutions, enlarging the old holes has not been sufficient. Often in the case of a machine room dis- posed above the shaft, another problem is how to pass the elevator hoisting ropes from the machine room to the elevator car and counterweight in the shaft.

The object of the present invention is to overcome the above-mentioned drawbacks and to reduce the size and/or weight of an elevator machine by providing an economical and simple-and-easy-to-implement possibil- ity of using drive and diverting pulleys of a smaller diameter by changing the elevator suspension in con- nection with modernization into an N: 1 suspension,

where N has at least an integer value in the range of 2... 16. A good practical application will be achieved when the value of N is 4. In particular, even values of the car suspension ratio are quite simple to imple- ment. For example, by increasing the number of divert- ing pulleys on the car to three, a 6: 1 suspension ra- tio is obtained, while four diverting pulleys will give a suspension ratio of 8: 1 and five diverting pul- leys a suspension ratio of 10: 1. This of course means that diverting pulleys will have to be added to other parts of the elevator as well and the total length of the ropes is increased. On the other hand, increasing the suspension ratio enables the use of fewer parallel ropes, so the total rope length of the elevator ropes is not necessarily increased very much as the suspen- sion ratio is increased. An additional aim is to en- able the elevator ropes to be quickly and easily in- stalled. A further objective is to reduce the consump- tion of electricity.

The method of the invention for modernizing the hoist- ing function of an elevator is characterized by what is disclosed in the characterization part of claim 1, and the modernization arrangement of the invention is characterized by what is disclosed in the characteri- zation part of claim 6. Other embodiments of the in- vention are characterized by what is disclosed in the other claims.

By applying the invention, one or more of the follow- ing advantages, among others, can be achieved: - due to thin hoisting ropes and 4: 1 suspension, the traction sheave and the diverting pulleys are small and light as compared with those used in conven- tional elevators

with a small traction sheave, the operating brakes of the elevator are smaller due to the small traction sheave, the torque re- quirement is lower, and thus both the motor and its operating brakes can be smaller due to the smaller traction sheave and 4: 1 suspen- sion, a higher rotational speed is needed to achieve a given speed of the elevator car, so the same motor output power is achieved with a smaller motor the use of a small traction sheave makes it possible to use an elevator drive motor of smaller size, which means a reduction of the acquisi- tion/manufacturing costs of the drive motor the small size and thin ropes allow relatively easy disposition of the elevator machine in the machine room the weight of the elevator car and counterweight can be completely or at least partially carried by the elevator guide rails in elevators applying the invention, centric suspen- sion of the elevator car and counterweight can be easily arranged, thus reducing the lateral support- ing forces imposed on the guide rails the invention reduces the elevator installation time and the total installation costs as compared to a situation where new holes would have to be made in the bottom of the machine room the light, thin and easy-to-handle ropes and the possibility to drop the ropes from the machine room into the elevator shaft allow considerably easier and faster installation by using ropes of a diameter of about 4... 6 mm, eleva- tors according to the invention of a fairly large

size and capable of fairly high speeds can be achieved - the invention is applicable in geared and gearless elevator motor solutions.

The primary sphere of application of the invention is in elevators designed for the transportation of people and/or freight. The elevator solution of the invention uses ropes that are thinner than those used before in elevators to be modernized, preferably substantially thin ropes having a diameter of e. g. about 4... 6 mm or even less. This allows a definite reduction in the size of the traction sheave and diverting pulleys.

In the following, the invention will be described in detail with reference to an embodiment example and the attached drawings, wherein Fig. 1 presents a diagrammatic view of an elevator modernized by the method of the invention, seen obliquely from above, in which an ear- lier 2: 1 suspension has been replaced with 4: 1 suspension, Fig. 2 is a diagrammatic and simplified illustration of the principle of the invention for lower- ing the elevator ropes into the elevator shaft, seen in side view, and Fig. 3 presents an oblique top view of an installa- tion tool applicable for lowering a diverting pulley aggregate into the elevator shaft.

Fig. 1 presents a typical elevator suspension solution 1 according to the invention, wherein an earlier 2: 1 suspension has been changed in conjunction with mod- ernization to a 4: 1 suspension by using openings 16 ready made in the machine room floor 15. The elevator hoisting machine is connected via a traction sheave 9

to a set of hoisting ropes, consisting of mutually parallel hoisting ropes 4 of e. g. substantially round cross-section and supporting the counterweight 3 and elevator car 2 moving along their tracks, i. e. guide rails. For the sake of clarity, only one of the paral- lel hoisting ropes 4 is shown in the figures.

The parallel hoisting ropes 4 are attached by their first end to a fixed starting point 5 in the machine room above the elevator shaft, from where the hoisting ropes go downwards through an opening 16b in the ma- chine room floor 15 towards a first diverting pulley 6 connected to the counterweight 3 and disposed e. g. on the top of the counterweight 3. From diverting pulley 6, the elevator ropes go upwards to a second corre- sponding diverting pulley 7 disposed in the machine room above the elevator shaft. The ropes going upwards are passed through an opening 16a in the machine room floor 15. Having passed around the traction sheave 7, the ropes 4 go again downwards through opening 16a to a second diverting pulley 8 which is mounted on the top of the counterweight 3 and which is of the same size with the first diverting pulley 6 and is placed right beside the latter, the shafts of both diverting pulleys being mounted one after the other on the same line, and which diverting pulley 8 rotates about its shaft in the opposite direction to that of diverting pulley 6. Having passed around the second diverting pulley 8, the hoisting ropes 4 go upwards through the opening 16b in the machine room floor to the traction sheave 9 of the elevator machine in the machine room.

Thus, the ropes 4 have been passed four times through each opening 16a and 16b.

Having passed over the traction sheave 9, the hoisting ropes 4 pass over a diverting pulley 10 and go again downwards into the elevator shaft from the machine

room through a third opening 16c in the machine room floor 15. By means of diverting pulley 10, the ropes are shifted horizontally to the correct position above opening 16c. From diverting pulley 10, the hoisting ropes 4 go downwards to a first diverting pulley 11 placed on the top of the elevator car 2, and having passed around this diverting pulley the ropes go up again through a fourth opening 16d in the machine room floor 15 to a diverting pulley 12 placed in the ma- chine room. Having passed around diverting pulley 12, the hoisting ropes 4 go again downwards through open- ing 16d to a second diverting pulley 13 placed on the top of the elevator car 2, which diverting pulley is of the same size with the first diverting pulley 11 and is placed right beside the latter, the shafts of both diverting pulleys 11 and 13 being placed one af- ter the other on the same line, which diverting pulley 13 rotates about its shaft in the opposite direction to that of diverting pulley 11. Having passed around the second diverting pulley 13, the hoisting ropes 4 go upwards again through opening 16c in the machine room floor to a fixed anchorage 14 in the machine room. Thus, the ropes 4 have been passed four times through openings 16c and 16d as well.

To make it possible for the hoisting ropes 4 to be passed twice through all the openings 16a... 16d in the machine room floor 15, the fixed points 5 and 14, di- verting pulleys 7 and 12 and the traction sheave 9 and diverting pulley 10 have to be so disposed that the hoisting ropes running in different directions through the holes 16a... 16d will not hinder each other's pas- sage. According to the invention, the above-mentioned devices are additionally so disposed that the openings 16a... 16d ready made in the machine room floor 15 and designed for 2: 1 suspension will be sufficient for all the required rope passages through the floor. There-

fore, for example the rope anchorages 5 and 14 a dis- posed above or in connection with the openings closest to the machine and the traction sheave 9, i. e. the middlemost openings 16b and 16c.

Similarly, diverting pulleys 7 and 12 are placed mutu- ally above or in connection with the outermost open- ings 16a and 16d which are closer to the side walls of the machine room, and these diverting pulleys have been suitably rotated and turned relative to their shafts to allow the ropes to be passed through the floor. In addition, if necessary, diverting pulleys 7 and 12 are provided with a structure that allows them to move so that no extra strain is imposed on the hoisting ropes 4 when the rope angle is slightly changed as the elevator car and counterweight move from the upper end of the elevator shaft to its lower end and vice versa.

Fig. 2 illustrates a principle according to the inven- tion for lowering the hoisting ropes 4 from the ma- chine room into the elevator shaft in conjunction with modernization as mentioned above, wherein an earlier 2: 1 suspension is changed into a 4: 1 suspension. When the hoisting ropes 4 are being lowered from the ma- chine room into the elevator shaft, there is often the problem of how to get the ropes neatly and easily down, because the risk of the thin and long parallel ropes becoming twisted and entangled in the narrow space is very great. In addition, making a skein of rope even slightly entangled descend is difficult if it is only pulled by the weight of the rope itself.

According to the invention, when the ropes are to be lowered down, the diverting pulleys 11,13 and 6,8 to be mounted on the top of the car and counterweight are used as weights and to keep the ropes as wide apart from each other as possible. The rope to be mounted to

run around the diverting pulleys 6 and 8 of the coun- terweight 3 is mounted by first driving the elevator car 2 to the upper end of the elevator shaft, where it is secured in place by means of ropes or tackles or equivalent. The counterweight 3 is now correspondingly at the lower end of the elevator shaft, where it is secured and the old elevator ropes are removed.

In the machine room, diverting pulleys 6 and 8, which have been combined to form a suitable diverting pulley aggregate 17, which can be passed through an opening 16a... 16d in the machine room floor into the elevator shaft space. In the diverting pulley aggregate 17 ac- cording to the example, diverting pulleys 6 and 8 are placed side by side in accordance with their final op- erating positions.

When everything is ready in the elevator shaft for the installation of the ropes, the installation is started e. g. with the elevator ropes suspending the counter- weight. First, the elevator ropes are fitted onto the diverting pulleys 6 and 8 to be attached to the coun- terweight, in the manner the ropes will run in the fi- nal operating position. The first end of the hoisting ropes 4 is pulled from a reel 18 in the machine room first around diverting pulley 8, whereupon the ropes are passed further to diverting pulley 7, which has already been secured in the machine room, and over it further around diverting pulley 6, after which the first end of the ropes is secured to a fixed starting point 5 in the machine room. In this connection, all the diverting pulleys 6... 8 are also provided with sup- porting elements to ensure that the hoisting ropes can not come off the rope grooves of the diverting pul- leys.

The diverting pulley aggregate 17 provided with ropes, which comprises at least rope pulleys 6 and 8, is now

lowered down through opening 16a or 16b in the machine room floor into the elevator shaft, the aggregate be- ing supported by the hoisting ropes. In the elevator shaft, at least one person is standing on the top of the elevator car to receive the aggregate, who reaches up to the diverting pulleys and takes them down at first e. g. onto the top of the elevator car. After this, on the top of the car, a framework as illus- trated in Fig. 3 serving as an installation tool is mounted around the diverting pulley aggregate 17 con- sisting of diverting pulleys 6 and 8.

The framework shown in Fig. 3 has a frame structure consisting of two parallel horizontal square tube shaped frame beams 21 connected to each other. At the outer end of each frame beam 21 is a substantially vertical guide beam 20, the upper and lower ends of which are provided with guide elements 23 fitted to receive the counterweight guide rails and, if neces- sary, the car guide rails of the elevator as well. The horizontal distance between the guide beams 20 can be adjusted to fit the distance between the guide rails in the elevator shaft. This adjustment is made by mov- ing the guide beams 20 in the longitudinal direction of the frame beams 21 and locking the guide beams in place by means of a locking element 22. If necessary, the installation tool can be provided with additional weights 19 to facilitate the lowering of the ropes from the machine room.

After the installation tool has been assembled around the diverting pulley aggregate, the installation tool is mounted on the guide rails of the counterweight 3 so that the guide elements 20 can move along the coun- terweight guide rails. The rope is let down from the reel 18 in the machine room and the installation tool with the diverting pulleys 6 and 8 is allowed to glide

downwards along the counterweight guide rails until the diverting pulley aggregate hits the top beam of the counterweight 3 in the lower part of the shaft.

Next, the diverting pulley aggregate is secured to the counterweight and the installation tool is removed.

The use of the above-described installation tool pro- vides the advantage that the ropes remain straight throughout the lowering procedure and can not be e. g. twisted about each other. A further advantage is that the mass of the installation tool alone is generally sufficient for lowering the diverting pulleys, requir- ing no additional weights.

The above-described method and also the installation tool, if necessary, can be applied for installing the diverting pulleys 11 and 13 to be mounted on the top of the elevator car 2 and likewise for lowering the hoisting rope. However, as the distance from the ma- chine room to the top of the elevator car 2 in its high position is short and the installation on the top of the car is easy to carry out in respect of space available, the use of an installation tool can in most cases be omitted. In this case it is thus sufficient that the diverting pulley aggregate ready provided in the machine room with ropes as described above and comprising at least diverting pulleys 11 and 13 is lowered down through a suitable opening 16a... 16d in the machine room floor and received directly on the top of the elevator car and mounted in place.

It is obvious to the person skilled in the art that different embodiments of the invention are not limited to the example described above, but that they may be varied within the scope of the claims presented below.

According to the examples described above, the skilled person can vary the embodiment of the invention e. g. by placing the rope anchorages 5 and 14 and the di-

verting pulleys 7 and 12 of the machine room in posi- tions differing from the above description. If possi- ble, the fixing points 4 and 5 may also be disposed in the upper part of the elevator shaft right below the floor of the machine room. In this case, there will be even more space for the hoisting ropes in openings 16b and 16c. it is also possible to place both the fixing points 4 and 5 and diverting pulleys 7 and 12, or only diverting pulleys 7 and 12, in the elevator shaft be- low the floor of the machine room as described above.

In this case there will be more space for the hoisting ropes in openings 16a and 16d as well.

It is further obvious to the skilled person that the shape and installation-time use of the diverting pul- ley aggregates 17 facilitating the installation work may differ from the above description. Thus, the vari- ous devices can be installed and made ready for opera- tion by an installation procedure differing from that described above. Similarly, depending on the dimen- sions, the diverting pulleys may be placed in the di- verting pulley aggregate 17 either side by side, as in the example, or they may also be place one under the other. Likewise, the size, number and location of the openings 16a, 16b in the machine room floor may be different from those described above.

It is also obvious to the person skilled in the art that, when the car is being moved, the parallel di- verting pulleys 6 and 8 connected to the counterweight 3 and the parallel diverting pulleys 11 and 13 con- nected to the elevator car 2 may rotate either in the same direction or in opposite directions relative to each other, depending on the arrangement of the ropes and diverting pulleys, so that the circumferential speed of the parallel diverting pulleys of the eleva- tor with 4: 1 suspension is 2: 1.

It is further obvious to the skilled person that, al- though the preferred embodiment of the invention uses fairly thin ropes, the invention is also applicable in the case of elevators in which the new ropes are clearly thicker than these ropes. For example, a mod- ernization wherein earlier 12-mm ropes are replaced with 8-mm ropes may be included in the scope of the invention.