During the construction of high-rise buildings, elevators are needed before the building has been finished. Either the ele- vators are needed for construction time use or the lower floors are completed before the rest, in which case the ele- vators serving them must be available for use. As the con- struction work is advancing, the elevator must be able to serve as many floors as possible.

For construction time use, so-called jump elevators have been developed, in which the hoisting height of the elevator is increased gradually as the construction work advances. The elevator machine room is moved to an upper level and the length of the elevator rope is increased correspondingly. A general requirement concerning elevators is that the elevator should be usable in its entirety and with all its properties.

Therefore, all other components depending on the hoisting height, such as the car cables, compensating ropes, overspeed governors and the electrification and electric cables in the hoistway should also be extended through the whole length of the finished hoistway.

From specification US 5,033,586, a solution is known in which the elevator machine room can be raised to and mounted at a desired height. In this solution, a second deck with a rope supply is disposed above the machine room. When the machine room is to be moved, the elevator car is locked in place so that it remains immovable with respect to the machine room and the required additional rope length is taken from the rope supply. In this solution, the rope supply must be lifted along with the machine room, an extra deck must be built and a complex apparatus is needed for paying out the additional rope.

The object of the present invention is to achieve an economic elevator for construction time use which, with the progress of construction work, can be easily lifted to a higher work- ing level and which is also suited for use as the regular elevator of the building. To implement this, the invention is characterized by the features presented in the characteriza- tion part of claim 1. Other preferred embodiments of the in- vention are defined in the subclaims.

The solution of the invention allows easy provision of the additional rope length needed as the height of the building increases. When the machinery is moved to a new working level, all components of the elevator are always immediately available for use without complicated adjustments or set- tings. Those portions of the hoist rope and compensating rope which are not yet in use can be freely disposed in a suitable place, even in a space outside the building. The equipment in the machine room used during construction constitutes the elevator machine room of the finished building as far as ap- plicable.

In the following, the invention will be described in detail by the aid of one of its embodiments with reference to the drawings, wherein -Fig. 1 presents an elevator according to the invention, and -Fig. 2 presents another elevator according to the inven- tion.

Fig. 1 illustrates the elevator system of the invention.

Mounted in the upper part of the finished part of a hoistway, which is defined by side walls 28 and 30 and a back wall 29, is a machine room deck 22, which carries the elevator drive machine 18. The drive machine 18 consists of an elevator mo- tor, possibly provided with a gear, and a traction sheave driven by it. An elevator rope 4 has been fitted to run over the traction sheave and attached by one end to the car 2 or

car frame. On the other side of the traction sheave, the ele- vator rope runs over a diverting pulley 20 and via a divert- ing pulley 54 mounted in the upper part of the counterweight 56 back to the machine room deck 22, from where the elevator rope 4 is further passed over a diverting pulley 55 and fixed substantially at the level of the machine room deck 22 by means of a clamp 24 fastened to the hoistway or building structures. In this example, the elevator car is implemented using a 1: 1 suspension ratio, so the circumferential velocity of the traction sheave corresponds to the velocity of the elevator car. On the other hand, the counterweight is sus- pended with a ratio of 1: 2, so the velocity of the counter- weight equals half the circumferential velocity of the trac- tion sheave. Fixed in a known manner to the bottom of the elevator car 2 is a compensating rope 10, which is passed via a diverting pulley 12 in the lower part of the hoistway and via a diverting pulley 58 connected to the lower end of the counterweight to the bottom of the hoistway, where it is fas- tened to a rope clamp 26. Thus, the compensating rope as well as the elevator rope are suspended with a ratio of 1: 1 on the side of the elevator car and with a ratio of 1: 2 on the side of the counterweight. As for the hoisting machinery and com- pensating ropes, the elevator works in the normal manner.

That part 6 of the elevator rope which is not in use during construction hangs freely below the clamp 24 and the extra rope is spooled on rope reels in a rope supply 8. The rope supply is preferably located in the lower part of the build- ing at or below the level of the first temporary position of the machine room deck. Similarly, the extra portion 14 of the compensating rope behind clamp 26 is stored on rope reels in rope supply 16.

The overspeed governor rope 32 is attached by one end to the elevator car and passed via a diverting pulley 35 in the lower part of the hoistway to the overspeed governor wheel 34. The overspeed governor rope 32 is fastened to a clamp 36

on the top of the car and the free rope portion 38 is stored in an overspeed governor rope supply 40 placed on the top 42 of the car.

Provided on the machine room deck or on another deck 48 lo- cated near it is a space for a control panel 52 and an eleva- tor control unit 50. Deck 48 is connected to deck 22 in such a way that both decks can be raised together as the construc- tion work advances. The supply of electricity to the elevator car and the control of the car equipment are implemented in a manner known in itself by using a car cable 43, which is con- nected to the elevator car 2 and to the elevator control unit 50. To allow for future hoisting heights, a car cable supply 44 is provided on the machine room deck 22. Correspondingly, a hoistway cable supply 46 for hoistway wiring 45 is likewise provided on the machine room deck 22.

Fig. 2 presents another example of an embodiment of the in- vention, in which the compensating system is implemented us- ing chains 60. In this case, no continuous compensating rope and no rope supply for it are needed, but when the machine room is moved to a higher level, the compensating chain 60 is extended with the required length of additional chain. In other respects, the arrangement in Fig. 2 corresponds to the solution illustrated in Fig. 1 and corresponding parts are indicated by the same reference numbers as in Fig. 1.

When the machine room of the elevator is to be raised to the next level, a procedure as described below is observed. The elevator car is driven in service operation mode to the high- est position possible. The counterweight is now in its low position, and it is made fast and locked in place. After this, the car is secured in place e. g. by locking it to the guide rails or in some other reliable manner. The rope clamps of the hoist rope and compensating rope are released, where- upon the required additional rope length can be paid out from the rope supplies. The rope clamp holding the overspeed gov-

ernor rope is loosened so that the rope can slide during the hoisting of the machine room. The wires connected to the ele- vator control panel are disconnected.

The elevator machine room and its supporting beams are raised somewhat by means of a crane or construction hoist (not shown), whereupon the supporting means of the machine room structure can be released. The machine room is raised to the next machine room level by means of a hoist or by some other applicable hoisting method. During the raising, the hoist ropes and compensating ropes run freely from the rope reels of the rope supplies. Similarly, a length of overspeed gover- nor rope is spooled off from the overspeed governor rope reel on the top of the elevator car. Likewise, lengths of car and hoistway cable corresponding to the lift are released from the car cable and hoistway cable reels on the machine room deck.

After the machine room deck has been hoisted to the new posi- tion, the supporting means of the machine room deck are acti- vated and the machine room supporting beams are reliably se- cured to the building. The overspeed governor rope is fixed to the top of the car. The elevator car is hoisted to the highest level by means of a hoist or crane, whereupon the hoist ropes and compensating ropes are secured, tightened to the right tension and locked in place by means of rope clamps. The counterweight is released and the car and hoist- way cables are secured and connected to the control panel.

After this, the elevator is ready to serve the new floors.

In the case of elevators in which the compensating system is implemented using chains, the compensating chain is extended before the machine room deck is hoisted to the new working level.

There are numerous different alternatives for implementing the securing of the car and counterweight during the hoisting of the machine room. Likewise, the hoisting of the machine

room and the elevator car can be implemented using one of several alternative methods. Similarly, there are several methods applicable for locking the rope in practice during construction time use. The payout of rope from the rope sup- plies can be similarly effected in various ways. The location of the rope supply can be selected in each building according to the possibilities available. The control panels and con- trol unit in the machine room may also be located on the same level with the hoisting machine.

Once the building has reached its final height, the construc- tion time machine room together with the hoisting machine and other machine room equipment can be left permanently in place, so that they form a corresponding part of the machine room. The rope supplies and other equipment used temporarily during construction are now unnecessary and they are natu- rally removed.

The above description is not to be regarded as a limitation of the sphere of patent protection, but the embodiments of the invention may be freely varied within the limits defined by the claims.