When elevators are installed in old buildings, it is often necessary to use solutions that take up as little space as possible. If the spaces at the top and bottom of the elevator shaft are to be enlarged, the work is often either impossible to implement in view of constructional aspects or expensive to carry out. Still, safety spaces for maintenance purposes as required by safety regulations have to be provided above and below the car.

According to Finnish application 980594, to ensure the re- quired safety space, a safety buffer arrangement provided for maintenance purposes at the bottom of the elevator shaft is known. The safety buffers according to said application can be arranged in the path of the elevator car so as to prevent the car from moving downward beyond a certain distance from the bottom of the shaft and likewise below the counterweight to prevent the car from moving upward beyond a certain dis- tance from the top of the shaft. The safety devices according to this specification are arranged on the bottom of the shaft in a lying position, from which they can be raised into the path of the car or counterweight when necessary. However, when lying on the bottom of the shaft, they take up some space in the vertical direction as well, and so they are not applicable in solutions where the space below the car is very small. Another way of providing a safety space is to use re- movable buffer beams, which are mounted in place temporarily to allow maintenance operations when a safety space is needed. However, the known solutions occupy a space under the car when it is moving and are difficult to automate.

The object of the invention is to disclose a new type of safety device designed to ensure a sufficient space above and below the elevator car in a maintenance situation in the case of elevators having a small shaft space.

The invention is based on the idea of making as efficient use of the empty space at the shaft bottom as possible so that the safety device need not take up any space in the vertical direction under the car unit (consisting of the car and the car frame) during normal operation of the elevator. Placing the safety device in the space between the counterweight and the car unit on the bottom of the shaft allows it to remain out of the way of the car unit when the latter is moving.

When necessary, the safety device of the invention prevents the motion of the car unit by being turned to a position un- der the car unit, with the result that buffers attached to the underside of the car unit hit the safety device and the car unit stops at a certain height from the shaft bottom.

The invention is characterized by what is presented in the characterization part of claim 1. Other embodiments of the invention are characterized by what is presented in the other claims.

By using a safety device according to the invention, an ad- vantageous implementation of a safety space with a small movement is ensured. The safety device of the invention can be easily automated. Being placed between the car unit and the counterweight, it does not occupy any space under the elevator when the latter is moving. Therefore, it can be used in elevators having a very small space below the car. This safety device can also be used in other types of elevator.

The safety device has a plate-like structure that also allows it to function as a guard structure between movable parts in the shaft.

In the following, the invention will be described in detail with reference to the attached drawings.

Fig. 1 presents a safety device according to the invention.

Fig. 2 presents the safety device in normal position.

Fig. 3 presents the safety device in operating position.

Fig. 1 presents a safety device 1 according to the invention, made of a durable material, such as steel, comprising a plate-like stopping device hinged on the shaft bottom by piv- ots 6. Fitted on the upper end of the stopping device is a rail 5 provided with two supports 8 designed to meet safety buffers attached to the underside of the car unit 9. The safety buffers may also be mounted on the safety device, and their function is to dampen the impact. The car unit com- prises the car and the car frame or only the car. The safety device turns on its pivots 6 between a normal position and an operating position. The safety device also comprises a lock- ing device 7, which locks the safety device 1 in the operat- ing position. The locking device can be opened and closed manually. In addition to the locking device, the safety de- vice also comprises a holding mechanism 20, such as a magnet, designed to hold the safety device in the operating position.

The magnet grabs the elevator guide rails. The holding mecha- nism also holds the safety device in the normal position, with the magnet grabbing a shaft structure and thus holding the device in an upright position. The safety device is pro- vided with a micro switch for identifying its position and giving the elevator control system data indicating a safety guarding position.

In Fig. 2, the safety device 1 is in the normal position, which is used when the elevator is operating normally between floors. The safety device is placed on the bottom 10 of the shaft in a space 14 between the counterweight and the car unit. The car unit comprises a car 19 and a car frame 18 or only a car 19. Space 14 comprises the space between one outer edge 15 of the car unit and a shaft wall 13, in which space the counterweight 16 is moving. The figure shows the counter- weight 16, although in reality it cannot be in the lower part of the shaft when the car unit is at the bottom floor. In the situation presented in the figure, the car unit 9 has reached the bottom floor. It can be seen that the safety device is well applicable for use in a solution with a small space be- low the car as it does not take up any space under the car unit when the latter is moving.

When there is a need to work above the car unit 9 on the top of the car, the car unit is first stopped at a position where the serviceman can get onto the car top after having opened the doors 11. To ensure a top safety space for the service- man, the top of the car unit is provided with a rail-like safety device 12 that can be turned on the top of the car unit into a safety guarding position.

Fig. 3 presents the safety device 1 in an operating position, in which it stops the car unit at a certain height from the shaft bottom 10, thus ensuring a safety space. The safety de- vice 1 is mounted on the bottom by pivots 6, of which there are a total of two for one safety device. When a serviceman wants to work on the shaft bottom, he first opens the door on the bottom floor, thereby preventing movement of the eleva- tor. Next, the serviceman enters the shaft pit and releases the safety device 1 from its holding mechanism and turns it into the operating position, into the path of the car unit.

The safety device is now locked by the locking device and the holding mechanism, ensuring that a safety space exists in the pit. To restore the normal operating state of the elevator, the safety device is turned into its normal position, the up- right position, whereupon the person leaves the pit and the elevator control system is given data indicating that the elevator is allowed to move.

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