The general term"elevator"is used here to indicate an installation constructed for carrying either passengers or goods, so that the general term"loading platform"applies both to a cabin for passengers or to a cage for goods.

Basically, elevators are of two kinds, worked either by cables or by hydraulic means.

In both cases some space is usually required in which to install the machinery for operating the elevator.

Where an elevator is of the hydraulic type, the machinery includes a hydraulic drive unit comprising a tank for the fluid, a pumping unit with a positive-displacement pump and electric motor, and a set of valves to work the various stages of movement.

In the room housing the machinery, there are also electric or electronic control panels for operating movement of the loading platform, for power and for lighting.

The European elevator directive 95/16/CE and the certification systems for warranties and quality at present in use permit installation of elevators that do not require a room for machinery.

Several solutions have been adopted for cable-operated elevators, such as installation of the winch, flat, in the elevator shaft.

In the case of hydraulically operated elevators where a room for machinery is not provided, the drive unit is installed either in the pit, or near to one of the floor doors or else in a cupboard placed in some free space.

All these solutions present the following drawbacks.

If the drive unit is installed in the pit, any maintenance work required means taking the elevator out of service to allow the technician to get down into the pit.

This also means that the pit must be big enough for the purpose.

If the drive unit is installed near one of the floor doors, overall dimensions are greater than those needed for an elevator with a machine room. In this case, and in order to repair or replace faulty parts such as the electric motor for example, the whole of the adjacent structures must be taken down.

If the drive unit is placed in a cupboard outside the elevator shaft, space is needed for it that could be otherwise used.

Cooling of the hydraulic fluid is also more complex involving higher costs for refrigeration systems, or else imposing a reduction in the number of journeys per hour that the elevator can make.

The weight of the cupboard also adds to the difficulty of carrying and installing it.

The invention here described eliminates these drawbacks as will now be explained.

Subject of the invention is an hydraulically-operated means for elevators carrying either passengers or goods worked by an hydrau- lic drive unit of a flat, compact and substantially parallelepiped

structure, placed in the elevator shaft at the level of any stop made by the loading platform, between the wall of said shaft, in common with that of the landing, and the vertical guide of said loading platform nearest to said wall.

The rear wall of the drive unit substantially matches with the lateral wall of the elevator shaft.

On the wall of the shaft in common with that of the landing, an aperture, at the position of the lateral wall of the drive unit, is made to permit said drive unit to be passed through it laterally.

At the position of the aperture made in the wall of the landing, to permit passage of the drive unit, there is a cupboard with a door at the front and having an internal side substantially aligned with the lateral wall of the elevator shaft to allow the drive unit to fit in between the loading platform guide and said door.

The drive unit can slide freely sideways using sliding means above and below.

The drive unit\'s upper guiding means consists of a bar placed on the lateral wall of the elevator shaft, said bar extending onto the internal side of the cupboard and being substantially aligned with said shaft.

Mounted by pins on said bar are pulleys, in the races of which the upper horizontal end of a vertical rib, on the rear wall of the drive unit, slides freely.

The lower guiding means comprises horizontal carrying rollers fixed transversally by pins onto plates placed at the base of the drive unit\'s structure, said rollers sliding freely in a horizontal channel.

Said horizontal channel comprises a fixed section that extends between a bracket, fixed from the lateral wall of the elevator shaft to the nearest guide for the loading platform, to the landing, and comprises a mobile section, substantially the same as the fixed section and connected to it by a crosswise hinge that allows said

mobile section to stand vertically, against the lateral wall of the drive unit, or be laid flat on the landing, aligned with the fixed section.

The lower guiding means consists of a horizontal telescopic complex comprising a pair of guides fixed to the base of the drive unit, a fixed channel that extends between a horizontal bracket, fixed between the lateral wall of the elevator shaft and the nearest guide for the loading platform, and the landing, and comprises an intermediate freely sliding channel.

Space is made In the lower end of the drive unit structure for an oil tank while uppermost is the set of valves placed vertically and the control solenoids lying horizontally.

The invention offers evident advantages.

The fact that the drive unit can be completely drawn out by hand onto the landing where the elevator has stopped, enables any internal component to be reached without the mechanic having to enter the elevator shaft.

This ensures the necessary space and accessibility for ordinary or special maintenance and repairs, in complete safety.

Installation of the drive unit inside the elevator shaft, isolated from the outside, siginifies optimum cooling without the need for a system of refrigeration, and less noise perceptible from the landings.

Manual operation to bring the cabin to the nearest floor is done from the landing by pressing a button switch, there being thus no need to draw the drive unit out of its usual position.

The convenient position of the cupboard, one of whose sides is substantially aligned with the side wall of the elevator shaft, means that a part of the drive unit\'s sructure is situated in said cupboard, so further reducing the bulk of the whole installation when mounted.

Characteristics and purposes of the disclosure will become still clearer from the-following examples of its execution illustrated by diagrammatically drawn figures.

Fig. 1 Elevator shaft as in the invention, with extractable hydraulic drive unit, installed in place, and the cupboard beside the door opening at a landing, in perspective partially cut through.

Fig. 2 Elevator shaft, with the elevator, cross section.

Fig. 3 As above, with the drive unit being pulled out, cross section.

Fig. 4 As above, with the drive unit fully extracted, perspective.

Fig. 5 As in Figure 1, with the drive unit extracted, perspective.

Fig. 6 Detail of the upper guide system for extracting the drive unit, side view.

Fig. 7 Detail of the lower guide system for extracting the drive unit, side view.

Fig. 8 Detail of another version of the lower guide system for extracting the drive unit, perspective.

In Figures 1,3,4, the door at the shaft opening 25 on the landing 21 is not shown for simplicity.

The hydraulic drive unit 30 with its substantially flat and parallele- piped structure 31, which also houses a tank for oil, presents at the top a set of valves 35, the horizontally lying solenoids 36 for working the valves, and the button switch 37 for moving the cabin by hand in case of emergency.

The drive unit 30 is installed in the elevator shaft 20 for the elevator 10, said unit\'s rear wall 32 (Figures 2,3) substantially matching with the side wall 23 of said shaft, between the guide 15 of the elevator 10 and the door 61 of a cupboard 60 (Figure 1) placed in the front wall 22, with the door 26 (Figure 2) of the landing 21.

In the bottom 62 (Figure 5) of said cupboard 60 is an aperture 63 for passage of the drive unit 30 and, above said aperture, is the control panel 65 for movement, power and lighting.

The internal wall 64 of one side of the cupboard is substantially aligned with the side wall 23 of the elevator shaft 20.

The drive unit 30 can be drawn out onto the landing 21 sliding along a set of upper and lower guides.

The lower guide comprises a fixed channel 46 that extends from the horizontal bracket 45, fixed between the side wall 23 of the elevator shaft and the guide 15 of the elevator, to the landing 21.

The end of said channel 46 is joined to a second channel 47 substantially the same as the first, that, by means of a horizontal hinge 48, can bend vertically 47\' (Figure 7) against the side wall 33 of the structure 31 of the drive unit, or can lie horizontally on the landing 21 as an extension of the channel 46 (Figures 3,4).

The drive unit slides in the channels 46,47 facilitated by the rollers 40 supported by plates 41 and turning freely on pins 42.

The upper guide system for the drive unit comprises a horizontal bar 52 fixed onto the side wall 23 of the elevator shaft extending as far as the side 64 of the cupboard 60 and substantially aligned with said side wall 23.

By means of the pins 57, said bar 52 (Figure 6) supports the pulleys 55 within whose races 56 can freely slide the upper end of the flat rib 50 extending vertically from the rear wall 32 of the structure 31 of the drive unit.

Maintenance work is clearly facilitated by the fact that, on opening the door 61 of the cupboard 60 and lowering the front section 47 of the guide channel 46, the drive unit can be manually drawn right out onto the landing 21 where the elevator stops.

Alternatively, the lower guide for the drive unit is made as shown in Figure 8, with a pair of parallel guides 70 fixed to the lower wall of of the unit\'s structure 31, a channel 72 that extends from the horizontal bracket 45, fixed to the guide 15 of the elevator shaft 20, to the landing 21, and a freely sliding intermediate channel 71.