The present invention relates an elevator having a car that moves along at least one guiderail in a hoistway, and having at least one suspension rope that supports the car, and having a drive unit which has at least one drive motor with a traction sheave driven by it and working in conjunction with the one suspension rope at least, the drive unit being located in an upper section of the hoistway and projecting over at least part of the car.
From the technical article entitled xe2x80x9cAufzxc3xcge ohne Triebswerkraumxe2x80x9d (xe2x80x9cElevators with no Machine Roomxe2x80x9d) published in xe2x80x9cLift-Reportxe2x80x9d issue March 1998, an elevator without a machine room is known in which the drive unit is located on supports that are fastened to a hoistway wall in an upper section of the hoistway. Maintenance work is carried out on the drive unit from the roof of the elevator car. So as to be able to observe the drive unit. even when it is in motion, an installation platform is proposed which can be installed from a maintenance platform when required. This elevator requires relatively high hoistway headroom above the car. Furthermore, installing the maintenance platform, or installation platform, in the hoistway is relatively complicated.
Taking the above-described elevator as the starting situation, the purpose of the present invention is to propose an elevator which, while making good use of the space in the hoistway, meaning having a low hoistway height and small hoistway cross-section, assures safe access to the drive unit, especially if the car is jammed high in the hoistway.
To fulfil this purpose according to the invention, on an elevator of the type mentioned above, it is proposed that the car have a closable opening in its roof through which the drive unit is accessible.
With the elevator according to the invention, maintenance work is carried out from inside the car by use of a maintenance platform located inside the car. The closable opening provided in the roof of the car makes the motor accessible to a service mechanic.
The accessibility of the drive unit above the car is assured even when the car is jammed high in the hoistway. The dimensions of the opening in the roof can vary. In particular, the opening in the roof can comprise the entire car roof, thereby affording good access to the drive unit from all sides.
A significant advantage of the elevator according to the invention is that in addition to good use being made of the cross-section of the hoistway, the height of the hoistway can also be kept very low, because maintenance work can be carried out from inside the car. Since the drive unit of the elevator according to the invention is not passed by the car, drive units of varying construction and dimensions can be used, thereby giving great flexibility. In particular, drive motors with or without gears can be used according to choice. The elevator concept according to the invention can be used with various arrangements of suspension ropes. In particular, by means of return pulleys under the car, the suspension rope can be made to pass beneath the car, or instead of a traction sheave a winding drum can be used. The drive concept according to the invention can also be used on so-called rucksack-type elevators in which the car is guided on one side only. Since the drive unit is located in the upper section of the hoistway, which is also known as the headroom, different methods of fastening the drive unit can be used. For example, the drive unit can be fastened either standing on, or suspended from, transverse beams supported between the hoistway walls.
In an advantageous development, the opening in the roof excludes the area over which the motor projects. Here, the opening in the roof has such dimensions, and is so positioned, as to ensure provision of adequate safe space for the head and upper part of the body of the service mechanic standing in the car, and to avoid crushing parts of the body between the car roof and drive unit in all positions of the car.
It is advantageous for the opening in the roof to be closable by means of a lockable flap.
In an advantageous further development, the flap is connected to an unlocking device that is secured against unauthorized access. This unlocking device can be connected to a switching device in the switchbox that is accessible only to the service mechanic. In an advantageous further development, it is proposed that the flap be constructed so as to be detachable from the car roof and usable as a maintenance platform or part thereof. For example, the flap can be used as the tread surface of the maintenance platform. Further, the flap can have foldout supports so that in the detached state it can be converted into a maintenance platform. The maintenance platform can also be stepped, and have several tread surfaces of different heights.
In another advantageous development the flap is fastened to a supporting device on the roof of the car by means of which the flap can be moved into a maintenance position parallel to the roof of the car. The supporting device can have, for example, holding members constructed in the form of scissors.
An advantageous development has at least one stop to ensure a minimum clearance between the car and the drive unit. This stop can be constructed as a buffer that operates in conjunction with the counterweight.
In an advantageous development of the invention the drive unit is supported on at least one beam which rests on a hoistway wall, or on guiderails of the car, or on guiderails of the counterweight.
In an advantageous further development the one suspension rope at least passes over return pulleys under the car.
The drive unit can be constructed with gears, particularly planetary gears. As already mentioned earlier, a significant advantage of the elevator concept according to the invention is that there are no restrictions on the dimensions of the drive unit.