US 2927661 A
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March 8, 1960 KRlsTEK ETAL 2,927,661
ELEVATOR FOR 1.1mm; PERSONS OR' LOADS Filed Nov. 30, 1955 2 Sheets-Sheet 1 %g ga I j 5 WI D t INVENTORS. f'mamzeflfi lstek BY Eager: Rafa/2e? March 8, 1960 E. KRISTEK ETA!- 2, 27,661
ELEVATOR FOR LIFTING PERSONS OR LOADS Filed Nov. 30, 1955 2 Sheets-Sheet 2 Mel 2,927,661 ELEVATOR FUR LIFTING PERSONS R LOADS Emanuel Kristek and Eugen Reichel, G'ottw'aldov, Czechoslovakia, assignors to Zavody piesnho strojirenstvi Gtlanttwaldov, narodni podnik, G'ottwaldov, Czechoslova a Application November '30, 1955, Serial No. 550,130
Claims priority, application Czechoslovakia December 15, 1954 Claims. (Cl. 187-17) The present invention relates generally to improvements in elevators, and more particularly is directed to an elevator with a cage adapted to travel vertically or along an inclined path for lifting persons or heavy loads.
Most known elevators comprise a cage suspended by a cable from a hoisting mechanism or winch, and such elevators are of intricate construction owing to the indispensable requirements of safety, apart from having numerous other disadvantages. The cable has to be frequently checked and replaced and at higher velocities, dithculties are encountered by reason of the flow of air around the moving cage, so that the cross-sectiona1 area of the shaft has to be considerably greater than that of the cage. Furthermore, the arrangement of the hoisting or winch mechanism above the shaft increases the overall height of the building and disturbs its appearance, while the elevator cannot travel to the very top of the building.
The main object of the present invention is to provide an elevator that is free of the above disadvantages and has a number of characteristic advantages which will ap pear from the following description of illustrative embodiments.
In accordance with an aspect of this invention, an elevator comprises a cage movable in sealing engagement in an elevator shaft, with the cage being lifted or retained in its position by a difference between the air pressures in the shaft below and above, respectively, the cage. 7
The invention will be more clearly understood from the following description of illustrative embodiments thereof which is to be read in connection with the accompanying drawings, wherein:
Fig. 1 is a vertical sectional view of an elevator embodying the invention;
Fig. 2 is a horizontal sectional view of the cage included in the elevator of Fig. 1, and with a locking device provided in the cage being shown in an engaged position thereof;
Fig. 3 is a view similar to that of Fig. 2, but with the locking device shown in its released position;
Fig. 4 is a detail side elevational view of means provided in the elevator embodying the present invention for the purpose of connecting electrical equipment carried by the elevator cage with a source of electricity along the elevator shaft;
Fig. 5 is a diagrammatic side elevational view of another embodiment of the present invention; and
Fig. 6 is a diagrammatic view of an electro-hydraulic adjusting unit for controlling the movement of a valve included in each of the embodiments of the invention illustrated by Figs. 1 and 5, respectively.
Referring to Fig. 1 in detail, it will be seen that an elevator embodying the invention includes a cage 2 arranged for movement in a shaft 1 and having a floor 3 and ceiling 4 which are provided with sealing members 5 and 6 which extend into resilient engagement with the surface of shaft 1 for closing the space between the cage 2 and the shaft 1. A fan or blower 8 driven by a motor 10 is mounted adjacent the shaft in a chamber 7, and the discharge of the fan delivers air under pressure through a conduit 11 to the lower portion of shaft 1. The conduit 11 opens into the shaft at a distance a above its bottom. A pipe 12, adapted to be closed by a valve 14, branches off from the conduit 11 and opensinto the shaft 1 at the bottom of the latter, and a tube 15 also branches off from the conduit :11 and opens into a storage space or pressure accumulator 16.
The conduit 11 is provided with a non-return or check valve 17 permitting flow only in the direction toward the shaft 1, and conduit 11 is also provided with a control valve 18 operated by a unit 20 which, for example, may include an electric motor driving an hydraulic pump which supplies fluid to a cylinder having a piston slidable therein and connected to the valve 18, all in a known manner. The bottom of the shaft 1 is equipped with a spring buffer 21 preventing the cage 2 from abutting against the bottom of the shaft. At a distance b from the top of the shaft 1, a pipe 22 extends from the shaft to the chamber 7, where it is attached to the suction side or inlet of the fan 8. The pipe or conduit 22 is provided with a non-return or check valve 23 permitting flow therethrough only in the direction away from shaft 1, and a non-return or check valve 24- is mounted in a pipe 25 opening from conduit 22 to the atmosphere to admit atmospheric air in case a vacuum is formed in the conduit 22. The valves 17 and 23 are arranged in the manner described so as to allow the passage of air through the shaft 1 only in the upward direction.
The cage 2 (Fig. 2) is guided in the shaft 1 by means of rollers 30 which are rotatably carried by the cage and in rolling contact with the interior of the shaft. Cage 2 also is formed with a channel 31 (Fig. 1) passing vertically therethrough and adapted to be closed by a valve 32 which is controlled, for instance, by a unit 33 similar to the unit 20 previously mentioned herein. A suitable arrangement for the unit 33 is shown in Fig. 6 to include a reversible electric motor 33:: having its shaft 33b connected to a pump 330 for hydraulic fluid which is fed by the pump to one end or the other of a cylinder 33d having a piston 33e movable therein and connected, by a suitable mechanical linkage 33 to the valve 32 so that, by controlling the direction of rotation of motor 33a, the valve 32 may be opened and closed, as desired. The walls of the shaft are further equipped with metal rails 34 (Figs. 1, 2 and 4) which are suitably insulated from each other. Resilient contact strips 35 (Figs. 2 and 4) are mounted on the cage 2 and are adapted to move along the metal rails 34, to provide connections between electric equipment carried by the movable cage and other fixed electric equipment of the elevator. In order to exactly position the elevator cage at the individual floors, a known arrangement is employed that includes electromagnets 36 embedded in the well of shaft 1 and eifective, when energized, to actuate a magnetic relay 37 on the cage 2 of the elevator as such relay comes adjacent the energized electromagnet.
The cage is secured at the various floors by means of pawls 38 movably carried by the cage and adapted to be laterally projected from the latter to engage in apertures 39 in the wall of the shaft 1. The pawls 38 may be laterally projected (Fig. 2) and retracted (Fig. 3) by means of a unit 46) which may be similar to the unit 33 previously described with reference to Fig. 6, and which is connected to a link 40a which is, in turn, pivotally connected to a radial arm 40b extending from a centrally pivoted bell-crank 400. The opposite ends of bell-crank 400 are connected, by pivoted links or rods 49a, to the pawls 38 so that the latter are projected and retracted in response to rocking of bell-crank 460. The presently described embodiment of the invention is completed by an air-tight door 4-1 (Fig. l) for closing the usual opening in the shaft 1 at each lioor.
It may be proved by a simple calculation that, in order to cause the cage to float in the shaft, an air pressure capable of raising 300 to 400 mm. of water in a column has to act against the bottom of the cage. Such a pressure may be supplied by a two-stage, medium pressure fan with a relatively good efficiency, which is equal to the efficiency of existing elevator machines, particularly when the latter are equipped with worm gearings.
When the fan 8 delivers air to the conduit 11 and the valve 18 is more or less open, the pressure of air acts on the bottom of the cage 2, and, if the valve 32 is closed, the cage moves upwards. The air from the shaft above the elevator opens the check valve 23 and flows through the conduit 22 to the fan 8 in chamber 7. By this circulation of air the kinetic energy thereof is utilized and the consumption of new, unpurified air from the outside is reduced.
The cage is stopped at a selected fioor by the cooperation of the related electromagnets 36 with the magnetic relay 37 to close suitable circuits connected to units 20 and 40 by which the valve 18 is closed and the pawls 38 are pushed into the corresponding apertures 39 at the selected floor. When it is desired to again move the elevator cage, the valve 18 is opened and the pawls 38 are retracted or withdrawn.
During downward movement of the cage 2, the valve 18 is closed and the velocity of downward movement is controlled by the valve 32 past which air flows through the channel 31 from the space below the cage to the space above the cage.
The spaces a and b of the shaft 1 serve as air cushions at the opposite ends of the shaft and soften the impact of the cage at the limit of its upward movement or when the cage falls in the event of a failure of a part of the device.
The non-return or check valves 17 and 23 prevent the cage 2 from falling to the bottom of the shaft in case of stoppage of the fan or a sudden leak in the shaft caused, for instance, by the bursting of any of the doors 41 below the cage 2. The buffer 21 softens the impact of the cage 2 against the bottom of shaft 1 when the sealing members and 6 are damaged and prevents contact of the cage with the bottom surface of the shaft 1. If for any reason, the cage is displaced in the portion a of the shaft, it may be lifted by opening the valve 14 to admit air at an elevated pressure below the cage. During normal operation of the elevator, the valve 14 must be closed in order to insure the operation of the lower end portion a of the shaft as an air cushion. The storage space or accumulator 16 supplies air to shaft 1 below cage 2 if the rate of increase of the volume below the cage, during upward movement of the latter, momentarily exceeds the rate of delivery of air by fan 8.
It is one of the advantages of the elevator according to the invention that a plurality of elevators disposed at not too great a distance from each other may be operated by one motor and fan outside the building in which the elevator is mounted, and thus it is easy to achieve sound 4 insulation and to prevent vibrations from being transmitted to the building.
In the embodiment of the invention described with reference to Figs. 1-4 and 6, the channel 31 is opened in order to permit the cage to move downwards, and then connects the space below the cage with the space above the cage in the shaft. Under certain circumstances it may be preferable to effect such connection by means of a tube 310 provided outside the shaft, as shown in Fig. 5, and extending between the conduits 11a and 22a corresponding to the conduits 11 and 22 of the arrangement of Fig. l. The external tube 31a has a valve 32a therein corresponding to the valve 52 and similarly actuated by an electro-hydraulic device 33 so that, when valve 32a is opened, air can flow from the space in the shaft below cage 2 through tube 31a to the space above the cage, as indicated by the arrows in broken lines.
Although illustrative embodiments of the invention have been described in detail herein with reference to the accompanying drawings, it is to be understood that the invention is not limited to those precise embodiments, and that various changes and modifications may be effected therein by one skilled in the art without departing from the scope or spirit of the invention, except as defined in the appended claims.
1. An elevator for lifting persons or loads comprising an airtight elevator shaft, an elevator cage mounted for movement in said shaft, means for effecting airtight sealing of said cage in said shaft, fan means having a relatively low air pressure inlet and a relatively high air pressure discharge, first conduit means extending from said discharge and opening into said shaft adjacent the lower end of the latter, second conduit means opening from said shaft adjacent the upper end of the latter and extending to said inlet of the fan means so that the latter is operative to produce relatively high and low pressures in said shaft below and above, respectively, said cage for supporting, and causing upward movement of the latter in said shaft, adjustable valve means in said first conduit means for controlling the flow of air therethrough, a check Valve in said first conduit means permitting flow through the latter only in the direction from said discharge of the fan means to said shaft in order to prevent uncontrolled dropping of said cage in the event of a failure of said fan means, means defining a channel connecting the space in said shaft below said cage with the space in said shaft above the cage, and an adjustable valve interposed in said channel to close the latter during upward movement of the cage and to control the fiow of air through said channel from said space below the cage to said space above the cage during the controlled downward movement of said cage by gravity.
2. An elevator as in claim 1; wherein said first and second conduit means communicate with said shaft at locations spaced from said lower and upper ends, respectively, thereby to provide air cushions at the opposite ends of the shaft for preventing violent contact of said cage therewith.
3. An elevator as in claim 1; wherein said second conduit means has an aperture opening to the atmosphere and valve means in said aperture opening to permit the entry of atmospheric air when the pressure in said second conduit means falls below atmospheric pressure, said second conduit means further having a check valve therein interposed between said aperture and said shaft and permitting flow through said second conduit means only in the direction from said shaft to said inlet of the fan means.
4. An elevator as in claim 1; further comprising movable pawls carried by said cage and adapted to be laterally projected from the latter, said shaft having apertures in the walls thereof at predetermined locations and adapted to receive said pawls for releasably retaining said cage at said predetermined locations.
5. An elevator as in claim 1; wherein said first and second conduit means communicate with said shaft at locations spaced from said lower and upper ends, respectively, thereby to provide air cushions at the opposite ends of the shaft for preventing violent contact of 7 cage descends to a' level below the point where said first conduit means communicates with said shaft.
References Cited in the file of this patent UNITED STATES PATENTS 'Mabbs Jan. 11, 1887 Fordyce Oct. 27, 1896 Warren Oct. 8; 1901 Davy Apr; 13; 1920 Goddard June 20, 1950