The present invention relates to an elevator with double safety mechanism in which the first safety mechanism stops an elevator cabin in a result of an actuation of a blocking mechanism after reaching a predetermined acceleration, and the second safety mechanism is a buffer mechanism converting kinetic energy of an elevator cabin falling down into kinetic energy of rotational movement.

In known elevator constructions, such as for example the construction described in European patent application EP0922663, appropriate counterweights protecting an elevator cabin during falling down as well as impact plates absorbing kinetic energy of an elevator cabin falling down are used. In order to effect a rapid stoppage of an elevator in a shaft, rotated buffers are employed which in a result of rotation thereof induced by gravitational force contact a shaft framing.

Patent application US4032829 discloses a damping arrangement for employment between a rail-vehicle body and wheels, in which a part of energy of vibrations of a trolley is converted into electrical energy by means of a gear drive system with flywheels.

From international patent application W02004028864 a device is known for absorbing energy, in which kinetic energy is converted into kinetic energy of rotating masses. In this known solution an element absorbing energy is connected with two toothed bars which by medium of toothed wheels drive kinetic energy rotor accumulators in forms of rods with moveable weights slidably mounted on the rods. An appropriate progressivity of energy absorption is obtained in this known solution by employment of the moveable weights located as close to the rotation axis of the rotor with the rods as possible in order that a moment of inertia of the rotor in the initial phase of energy absorption be as small as possible. In further movement phase while the rotor starts to rotate, the weights start to translocate under influence of centrifugal force and move away from the rotation axis along the rod axis, until they reach the rod end limiters and in such weight positions the biggest moment of inertia of rotor is achieved that enables for absorption of the increased kinetic energy. International application WO2005121593 discloses a device for absorbing energy comprising a beater element cooperating with an energy dissipation arrangement comprising a toothed bar inducing rotation of rotating masses, thus causing a conversion of progressive movement kinetic energy resulted from an impact into kinetic energy of a rotational movement. In one of disclosed embodiments of this known solution, the toothed bar drives a rotor by means of a toothed wheel, wherein the rotor cooperates with a moveable weights. In order to provide a progressive change of a moment of inertia of the rotor during a process of an energy absorption, the moveable weights are maintained in appropriate distance from a rotation axis by means of springs.

The known solutions do not provide high efficiency of conversion of kinetic energy of progressive movement of an elevator cabin falling down into a kinetic energy of rotational movement, in different working conditions, in particular related with a mass and a falling down height. Therefore the object of the present invention is to provide higher efficiency of absorption of energy of an elevator cabin of different final kinetic energy.

According to the present invention the first safety mechanism constitutes an inertial blockade that jams the elevator cabin in the shaft after reaching a predetermined acceleration, and the second safety mechanism has a form of a buffer mechanism comprising a kinetic energy absorption rotor arrangement in which kinetic energy of progressive movement is transformed into kinetic energy of rotational movement, and which comprises a top plate and a bottom plate between which are arranged racks interengaged with toothed wheels driving the kinetic energy rotor accumulators of a given moment of inertia. The solution according to the present invention is characterized in that the kinetic energy absorption rotor arrangement, disposed on the bearing construction of the shaft floor, comprises at least two racks interengaged with the toothed wheels of the kinetic energy rotor accumulators of differentiated capabilities of energy accumulation, wherein the racks are installed between the bottom plate and the top plate defining differentiated gaps providing differentiated idle stroke between them and these plates.

The kinetic energy rotor accumulators of the kinetic energy absorption rotor arrangement preferably have differentiated moments of inertia. The kinetic energy rotor accumulators are preferably driven by means of toothed gears of differentiated transmission ratios that increase rotational velocities.

The idle stroke of the rack of the kinetic energy rotor accumulator having a capability of accumulation of higher energy is greater than the idle stroke of the rack of the kinetic energy rotor accumulator having a capability of accumulation of lower kinetic energy.

In the elevator according to the present invention an increased efficiency of absorption of energy of the elevator cabin falling down is achieved by inducing rotational movement of consecutive kinetic energy rotor accumulators of increasing moments of inertia or by inducing rotational movement of consecutive kinetic energy rotor accumulators which are gained with increasing rotational velocities by employment of gears of increasing transmission ratios that increase rotational velocities.

The elevator according to the present invention provides high efficiency of kinetic energy absorption during an elevator cabin fall from small heights as well as during an elevator cabin fall from big heights, in cases of big masses. In the first instance, the elevator according to the present invention provides efficient and very smooth shock absorption, as an absorption of kinetic energy of progressive movement takes place with using kinetic energy rotor accumulators of the smallest moment of inertia. In the second instance, the elevator according to the present invention also provides appropriately efficient and smooth shock absorption, as kinetic energy absorption takes place with using several rotor accumulators of increasing energy absorption capabilities.

In case of greater energy of an elevator cabin falling down an additional effect occurs consisting in that kinetic energy is in a great part accumulated in the rotor accumulators featuring lower energy absorption capability before the rotor accumulators featuring higher energy absorption capability are actuated. Such a sequence of energy absorption provides smoother operation of the chair according to the present invention during actuation of next rotor accumulators, even those of the greatest capability of energy absorption featuring the bigger moment of inertia. The exemplary embodiments of the present invention are presented below in connection with the attached drawings on which:

Fig. 1 presents a side view of an elevator shaft with the second safety mechanism exposed;

Fig. 2 presents an enlarged view of the section the elevator according to the present invention indicated in Fig. 1 ;

Fig. 3 shows a side view of the energy absorption rotor arrangement with rotor kinetic energy accumulators of the same moment of inertia with employment of toothed gears of different transmission ratios; and

Fig. 4 presents a side view of the energy absorption rotor arrangement with rotor kinetic energy accumulators of the differentiated moments of inertia with employment of toothed gears of different transmission ratios.

As presented in the embodiment of Fig. 1 and Fig. 2, the second safety mechanism, constituting a buffer mechanism of an elevator according to the present invention, has a form of an energy absorption rotor arrangement 1 , in which three racks 2 separated from each other are slidably mounted which by medium of toothed wheels 3 drive three kinetic energy rotor accumulators 4, 5, 6 of differentiated moments of inertia. Between the top plate 13 and particular racks 2 gaps 7, 8, 9 are formed defining an idle stroke of the top plate 13 relative to the racks 2. The gap 9 between the top plate 13 and the rack 2 driving the toothed wheel 3 of the kinetic energy rotor accumulator 6 efficient for accumulating the biggest energy is larger than the gap 8 between the top plate 13 and the rack 2 driving the toothed wheel 3 of the kinetic energy rotor accumulator 5 efficient for accumulating medium energy, whereas the gap 7 between the top plate 13 and the rack 2 driving the toothed wheel 3 of the kinetic energy rotor accumulator 4 efficient for accumulating the smaller energy is the smallest. In order to decrease impact in the initial stage, during contacting the top plate 13 with particular racks 2, between the top plate 13 and each rack 2 elastic shock absorbing elements are arranged in forms of springs 10. During a fall of the cabin 15, the top plate 13 of the kinetic energy absorption rotor arrangement 1 contacts the reinforced floor 16, and cabin 15 kinetic energy, resulting from its mass and a height of a fall, is transferred for driving kinetic energy rotor accumulators 4, 5, 6. The bottom plate 12 is embedded on the bearing construction 17 in the central part of the shaft 18 floor. Rolls 20 fixed by means of bearings in the cabin 15 framing slide in the shaped internal profiles of the beams 19. Furthermore, inertial blockades 21 are located in the vicinity of the internal profiles of the beams 15 and mounted in a swinging manner to the reinforced part of the cabin framing 19, which constitute the first safety mechanism of the elevator that effects jamming during a fall of the cabin 15.

The toothed wheel 3 and the kinetic energy rotor accumulators 4, 5, 6 are rotatively installed on the separated body plates 1 1 , whereas the racks 2 are slidably guided through the guides 14.

As shown in the embodiment of Fig. 3, in the kinetic energy absorption rotor arrangement 1 are employed kinetic energy rotor accumulators 6 of the same moments of inertia. A differentiation of capability of accumulation of kinetic energy of an elevator cabin falling down is in this embodiment obtained by employment of toothed gears of differentiated transmission ratio. In a case of toothed gear employment, a given transmission ratio is determined by the effective diameter of the toothed wheel 3a, 3b and 3c that cooperates with rack 2, and thus in the presented embodiments the kinetic energy rotor accumulator 6 driven by means of the toothed wheel 3a of the biggest effective diameter has the lowest kinetic energy absorption capability, the kinetic energy rotor accumulator 6 driven by means of the toothed wheel 3b of the medium effective diameter has the higher kinetic energy absorption capability, and the kinetic energy rotor accumulator 6 driven by means of the toothed wheel 3c of the smallest effective diameter has the highest kinetic energy absorption capability.

In the embodiment presented in Fig. 3, the toothed wheel 3a of the biggest diameter has the effective diameter two-fold bigger than corresponding diameter of the toothed wheel 3c of the smallest diameter, what in case of the same velocities of translocation of racks 2 and usage of kinetic energy rotor accumulators of the same moment of inertia results in that the kinetic energy rotor accumulator 6 driven by means of the toothed wheel 3c of the smallest effective diameter shall gain angular velocity two-fold greater than corresponding velocity of the kinetic energy rotor accumulator 6 driven by means of the toothed wheel 3a of the greatest effective diameter, thus it shall feature four-fold greater capability of rotational movement kinetic energy accumulation. The embodiment presented in Fig. 4 comprises kinetic energy rotor accumulators 4, 5 and 6 of differentiated moments of inertia and toothed gears of differentiated transmission ratios resulting from different effective diameters of the driving toothed wheels 3a, 3b, 3c. The kinetic energy rotor accumulator 6 of the biggest moment of inertia is driven by means of the toothed wheel 3a of the greatest effective diameter, and the kinetic energy rotor accumulator 4 of the smallest moment of inertia is driven by means of the toothed wheel 3c of the smallest moment of inertia. Such a construction provides a possibility of defining a smooth characteristic of a capability of kinetic energy during an impact of an elevator according to the present invention. In an alternative embodiment which is not illustrated on the drawing, where for driving the kinetic energy rotor accumulator of the greatest moment of inertia is employed a toothed gear with a toothed wheel of the smallest effective diameter, and for driving the kinetic energy rotor accumulator of the smallest moment of inertia is employed a gear with a toothed wheel of the greatest effective diameter, the biggest progressiveness of impact energy absorption shall be obtained.

In the described embodiments unidirectional couplings are also employed, though not presented on the drawing, and arranged between the toothed wheels 3 and kinetic energy accumulators 4, 5, 6. The function of these unidirectional couplings is transferring a torque onto kinetic energy rotor accumulators, and after absorption of energy, when angular velocity of the toothed wheel 3 shall be smaller than angular velocity of corresponding kinetic energy rotor accumulator 4, 5, 6, the unidirectional coupling is disconnecting thus it enables for unrestricted rotation of the kinetic energy rotor accumulator 4, 5, 6.

The best results are achieved in such an order of arrangement of the accumulators in which the rack having the smallest gap shall be guided along the line overlapping the center of gravity of the cabin 15.

In a result of a differentiation of widths of the gaps 7, 8, 9 the kinetic energy rotor accumulators 4, 5, 6 are actuated successively beginning with the kinetic energy rotor accumulator 4 of the smallest moment of inertia, and ending with the kinetic energy rotor accumulator 6 of the biggest moment of inertia. In a case of a bigger kinetic energy all kinetic energy rotor accumulators 4, 5, 6 shall be driven, wherein the kinetic energy rotor accumulator 4 of the smallest moment of inertia shall gain in such a case the highest angular velocity, the kinetic energy rotor accumulator 5 of the medium moment of inertia shall gain a medium angular velocity, and the kinetic energy rotor accumulator 6 of the greater moment of inertia shall gain the smallest angular velocity.