The present invention relates to an arrangement for the hoisting machinery of an elevator as defined in the preamble of claim 1.

In many cases the hoisting machinery of an elevator is located in a pit at the bottom of the elevator shaft. This can be a problem for example in case of a flood when water may enter the pit, in which case parts of the machinery can be damaged. Especially electrical parts may easily be damaged if they get wet. In addition, in the course of time dust and other dirt and debris collect in the pit, which also can damage or wear the machinery. Such dirt or debris may also increase the noise of the machinery.

Attempts have been made to solve the problems mentioned above. One solution is to locate the machinery above the first floor level so that if water enters the pit at the bottom of the elevator shaft it cannot reach the hoisting machinery. However, such a solution is often impractical and expensive and takes up unnecessary space in the elevator shaft. Also, the above-mentioned solution does not protect the machinery from dust and other dirt and debris.

One solution to solve the problem mentioned above is pre ^¬ sented in the Japanese patent publication No. JP2000177945A. The publication presents the solution where the elevator machinery is separated from the landing side of the elevator shaft by a separating wall that acts as a weir body and pre ^¬ vents water flooding upon the elevator machinery. A disadvantage of this solution is a need of a big shaft space that causes additional costs. Also water can enter the shaft from other side than the landing side, and also through the roof of the shaft. In that case the separating wall does not save the flooding situation but can make it even worse. Also, the separating wall is not good enough to protect the machinery from dust and other dirt and debris.

One object of the present invention is to eliminate draw ^¬ backs of prior art technology and to achieve an arrangement for the hoisting machinery of an elevator, which arrangement contains a protective casing for the machinery, which casing protects the machinery from water and other fluids, dust, dirt and other debris. Another object the invention is to achieve a standardized machinery unit, which is easy to in ^¬ stall and can be used in various kinds of elevators without making modifications. The arrangement according to the in- vention is characterized by what is disclosed in the charac ^¬ terization part of claim 1. Other embodiments of the invention are characterized by what is disclosed in the other claims . The invention makes it possible to achieve a standardized machinery unit, which is easy to install in many kinds of elevators without making modifications at the installation site, and can be used in various elevators where the hoist ^¬ ing machinery is located at the bottom of the elevator shaft regardless of differences in technical specifications of the elevators. The arrangement according to the invention also protects the hoisting machinery from water and other things, such as dust although the machinery is installed at the bot ^¬ tom of the elevator shaft.

Preferably the water and dust protection of the hoisting ma ^¬ chinery is done using a waterproof casing. Preferably the hoisting machinery is fitted inside the casing already at the factory to form a machinery unit and transported to the installation site and installed at the bottom of the eleva ^¬ tor shaft. Preferably the invention is expressed as an ar ^¬ rangement for the hoisting machinery of an elevator, which elevator comprises at least an elevator car arranged to run in the elevator shaft along guide rails, a counterweight connected to the elevator car with a traction member from below and suspension ropes from above, and a hoisting machinery equipped with a drive wheel in the lower part of the elevator shaft. The hoisting machinery is fitted inside a casing and the hoisting machinery and the casing together form a machinery unit.

The inventive content of the application can also be defined differently than in the claims presented below. The in- ventive content may also consist of several separate inven ^¬ tions, especially if the invention is considered in the light of expressions or implicit sub-tasks or from the point of view of advantages or categories of advantages achieved. In this case, some of the attributes contained in the claims below may be superfluous from the point of view of separate inventive concepts. Likewise the different details presented in connection with each embodiment can also be applied in other embodiments. In addition it can be stated that at least some of the subordinate claims can, in at least some situations, be deemed to be inventive in their own right.

One advantage of the arrangement according to the invention is that it protects the hoisting machinery from water, for example in case of a flood. Another advantage is that the hoisting machinery is also protected from dust, dirt and other debris, and also other fluids than water. Above- mentioned advantages lead to yet another advantage that the machinery can be normally located at the bottom of the ele ^¬ vator shaft so that it does not take unnecessary space else- where in the elevator shaft. Yet another advantage is that the casing belonging to the arrangement can be used also as a transport means to bring the machinery to the location of the elevator. A further advantage is that the casing or part of it can be made of such a material, which functions as a cooling surface. Yet a further advantage is that the ar ^¬ rangement contains a fan, which enhances cooling of the ma ^¬ chinery. Yet a further advantage is that the casing or ma ^¬ chine container can be pressurized using the fan. Yet a fur- ther advantage is that the hoisting machinery unit can al ^¬ ways be similar in many kinds of elevators without any modi ^¬ fications to be made or requiring only minor modifications. Yet another advantage is that the arrangement reduces the noise level of the machinery. Yet a further advantage is al- so that the solution is inexpensive and simple to implement.

In the following, the invention will be described in detail by the aid of example embodiments by referring to the at ^¬ tached drawings, wherein

Fig. 1 presents in a simplified and diagrammatic side view an elevator, in which the arrangement according to the invention can be used,

Fig. 2 presents the hoisting machinery of an elevator lo- cated at the bottom of the elevator shaft, which hoisting machinery applies the arrangement according to the invention,

Fig. 3 presents the hoisting machinery of an elevator, which hoisting machinery applies the arrangement ac- cording to the invention and

Fig. 4 presents in a simplified and diagrammatic side view one embodiment of the invention in case of a flood. The main idea of the invention is to have a casing or a container for the hoisting machinery of an elevator, which casing protects the machinery. With protective casing it is safe to locate the machinery at the bottom of the elevator shaft. The machinery and its casing together form a standardized machinery unit, which can be used in many kinds of elevators without having to make modifications at the in ^¬ stallation site. Figure 1 presents in a simplified and diagrammatic side view an elevator, in which the arrangement according to the invention can be used. The elevator comprises among other things an elevator car 1 that is fitted, for example inside a sling 2 and arranged to run up and down in the elevator shaft 3 along guide rails 4, and a counterweight or balance weight 5 that is also arranged to run up and down in the el ^¬ evator shaft 3 along its guide rails which are not presented in figure 1 for the sake of clarity. Later in this connec ^¬ tion only balance weight 5 is mentioned when either counter- weight or balance weight is meant.

The supporting and moving of the elevator car 1 are separated from each other. The elevator car 1 is driven by a hoisting machinery 6 equipped with a drive wheel 7. The hoisting machinery 6 is fitted inside a casing 9 at the bottom of the elevator shaft 3, below the elevator car 1 and below the first floor level 8.

A traction member 10 is connected between the balance weight 5 and the elevator car 1. The traction member 10 can be a single member or a bunch of similar parallel members, for instance, the traction member 10 can be a toothed belt, chain or other type of member that does not slip on the drive wheel 7. The first end of the traction member 10 is secured to the bottom part of the sling 2 of the elevator car 1 and from there the traction member 10 is guided down to go round the drive wheel 7 and then again up to the bal ^¬ ance weight 5. The second end of the traction member 10 is secured to the bottom part of the balance weight 5.

The elevator car 1 is suspended by suspension ropes 11 that are connected between the balance weight 5 and the elevator car 1. The first ends of the suspension ropes 11 are secured to the upper part of the balance weight 5 and from the bal ^¬ ance weight 5 the suspension ropes 11 are led upwards to go over and around a diverting pulley 12 that is journaled on its shaft at a support beam 13 which is fastened, for exam ^¬ ple, to the guide rails 4 above the elevator car 1. From the diverting pulley 12 the suspension ropes 11 descend to the elevator car 1 and are secured to the sling 2 of the eleva ^¬ tor car 1. At the bottom of the elevator shaft 3 there are also buffers 14. The placement of the hoisting machinery 6 and other elevator components at the lower part of the ele- vator shaft 3 can also differ from what is presented above.

Figure 2 presents the hoisting machinery 6 of an elevator fitted in a casing 9 and located at the bottom of the eleva ^¬ tor shaft and figure 3 presents the hoisting machinery 6 and its casing 9 alone. The hoisting machinery 6 is fitted inside the casing 9 and the hoisting machinery 6 and the cas ^¬ ing 9 together are called here the machinery unit 15. The machinery unit 15 is assembled at a factory and after that transported to its destination and installed to the bottom of the elevator shaft 3 as one unit. The hoisting machinery 6 and its casing 9, or the machinery unit 15 is installed inside a frame structure 21 and secured, for example, to the wall or walls of the elevator shaft 3 with help of securing means, which in this case comprise for example brackets, bolts and nuts. The machinery unit 15 is secured to the wall or walls of the elevator shaft 3 through the frame structure 21 so that the fastening bolts used do not penetrate the casing 9 and thus allow a situation for water to enter in- side the casing 9.

The casing 9 comprises a detachable cover 16. In figures 2 and 3 the cover 16 of the casing 9 is not attached to the casing 9, so the hoisting machinery 6 can be seen inside the casing 9. The detachable cover 16 is arranged to close the casing 9 so that the casing 9 is waterproof. The casing 9 and the detachable cover 16 can be made of the same material or the materials can also be different from each other. For example, the casing 9 can be made of plastic and the detach- able cover 16 of some metal, such as steel or aluminum. In such a case, the detachable cover 16 acts also as a cooling element. In this embodiment the detachable cover 16 is ar ^¬ ranged to be attached to the casing 16 with help of clips 16a .

At the upper part of the casing 9 there is an opening 17 for the traction member 10 to enter the casing 9 and to exit the casing 9 when the traction member makes 10 its turn around the drive wheel 7 inside the casing 9. As shown in the em- bodiment according to figure 4 there is a protection means 18 in connection with the opening 17 to prevent water from entering the casing 9, for example in case of a flood when water may enter the elevator shaft 3. The protection means 18 could be for instance a bellows-like cover or a corre- sponding means, which is arranged to rise along with water if the water surface level rises above the opening 17.

Also a ventilation pipe 19 belongs to the casing 9. The first end of the ventilation pipe 19 starts upwards from the upper part of the casing 9, then the pipe turns and part of the pipe 19 can be horizontal. After that the pipe turns again and the second end of the ventilation pipe 19 points downwards. The machinery unit 15 comprises also a drive 21 and there is also a fan 22 between the drive 21 and the hoisting motor of the hoisting machinery 6, which fan 22 is arranged to take care of ventilation of the hoisting machinery 6 through the ventilation pipe 19. Figure 4 presents a flood situation where the hoisting ma ^¬ chinery 6 is protected from water. The hoisting machinery 6 is inside the casing 9 and it is not visible in figure 4. The pit at the bottom of the elevator shaft 3 is filled with water and the casing 9 is protecting the hoisting machinery 6 from getting wet. The water surface level 20 has risen above the opening 17 at the upper part of the casing 9 and the water has raised the protection means 18 along the water surface so that water cannot enter inside the casing 9. The protection means 18 comprise a floating part 18a and a bel- lows part 18b. The floating part 18a floats on water and when the water surface level rises, the floating part 18a pulls the bellows part 18b up and the opening 17 is continu ^¬ ously protected from water. It is obvious to the person skilled in the art that the in ^¬ vention is not restricted to the examples described above but that it may be varied within the scope of the claims presented below. Thus, for instance, the elevator can also be different from the elevator described above. For example the suspension ratio of the elevator can be different.

It is also obvious to the person skilled in the art that the mounting of the machinery unit can also be done in a different way. For example, the machinery unit can also be secured to the floor of the elevator shaft instead of a wall or walls of the elevator shaft, or the machinery unit can be secured to both, the floor and wall or walls. It is further obvious to the person skilled in the art that the means that prevents water entering the casing through the opening can be different from what is presented above. For example, some other kind of means, which are triggered to seal the opening when the water surface reaches prede- fined level at the bottom of the elevator shaft. For example some kind of inflatable means, which are filled with air and seal the opening that way.