Abstract:
A mass rescue system including at least one upper rotatable support, at least one lower rotatable support disposed below the at least one upper rotatable support, at least one elongate flexible element wound about the at least one upper and at least one lower rotatable supports and at least first and second rescue platforms mounted on the at least one elongate flexible element at locations therealong arranged with respect to the upper and lower rotatable supports such that downward motion of the first rescue platform produces concomitant upward motion of the second rescue platform and vice versa, the first and second rescue platforms, when loaded to different weights, being operative to undergo upward and downward motion produced by gravitational acceleration and without requiring an external energy source.

Description:
REFERENCE TO RELATED APPLICATIONS  
       [0001]     Reference is made to U.S. Provisional Patent Application No. 60/546,006, filed Feb. 18, 2004 entitled “MASS RESCUE AND EVACUATION SYSTEM FOR HIGH-RISE BUILDINGS BY TWO BALANCED CABINS AND A FAN DESCENDER” the disclosure of which is hereby incorporated by reference and priority of which is hereby claimed pursuant to 37 CFR 1.78(a) (4) and (5)(i). 
     
    
     FIELD OF THE INVENTION  
       [0002]     The present invention relates to mass rescue systems generally, and specifically to mechanical mass rescue systems.  
       BACKGROUND OF THE INVENTION  
       [0003]     The following U.S. published patent documents are believed to represent the current state of the art:  
         [0004]     U.S. Pat. Nos. 6,830,126; 6,817,443; 6,808,047; 6,793,038; 6,598,703; 6,467,575; 6,318,503; 5,927,439; 5,562,184; 4,640,384; 4,616,735; 4,531,611; 4,433,752 and 4,424,884.  
       SUMMARY OF THE INVENTION  
       [0005]     The present invention seeks to provide a mass rescue and evacuation system designed for fast and easy evacuation of a large number of people from high structures.  
         [0006]     There is thus provided in accordance with a preferred embodiment of the present invention a mass rescue system including at least one upper rotatable support, at least one lower rotatable support disposed below the at least one upper rotatable support, at least one elongate flexible element wound about the at least one upper and at least one lower rotatable supports and at least first and second rescue platforms mounted on the at least one elongate flexible element at locations therealong arranged with respect to the upper and lower rotatable supports such that downward motion of the first rescue platform produces concomitant upward motion of the second rescue platform and vice versa, the first and second rescue platforms, when loaded to different weights, being operative to undergo upward and downward motion produced by gravitational acceleration and without requiring an external energy source.  
         [0007]     In accordance with a preferred embodiment of the present invention the mass rescue system also includes a dynamic resistance device operative to employ potential energy of the at least first and second rescue platforms for braking downward motion thereof. Preferably, the at least one elongate flexible element includes at least one first elongate flexible element which is wound over the upper rotatable support and at least one second elongate flexible element which is wound under the lower rotatable support. Alternatively, the at least one elongate flexible element includes a looped elongate element.  
         [0008]     In accordance with another preferred embodiment of the present invention the mass rescue system also includes at least one guiding element which is operative to guide the first and second rescue platforms. Preferably, the at least one guiding element includes at least one rigid element. Alternatively, the at least one guiding element includes at least one elongate flexible element.  
         [0009]     In accordance with yet another preferred embodiment of the present invention the mass rescue system also includes a counterweight operative to provide initial downward motion under gravitational acceleration and without requiring an external energy source. Preferably, at least one of the first and second rescue platforms includes a cabin. Additionally or alternatively, at least one of the first and second rescue platforms includes at least one guide assembly which rides along the at least one guiding element and which is operative to reduce transverse displacement of the rescue platform.  
         [0010]     In accordance with a further preferred embodiment of the present invention at least one of the first and second rescue platforms also includes a safety assembly operative to prevent free-fall of the rescue platform. Preferably, the mass rescue system also includes at least one stair unit associated with the first and second rescue platforms. Alternatively or additionally, at least one of the first and second rescue platforms also includes at least one door and at least one door safety element operative to prevent vertical motion of the rescue platform while the at least one door is open.  
         [0011]     In accordance with yet a further preferred embodiment of the present invention, at least one of the first and second rescue platforms also includes at least one of a first aid kit and a communications device. Preferably, the dynamic resistance device is operative to slow vertical motion of at least one of the first and second rescue platforms to a speed which is less than a predetermined speed. Alternatively or additionally, the dynamic resistance device also includes a reducing gearbox and a fan descender which are operative to slow the vertical motion of the first and second rescue platforms. Preferably, the dynamic resistance device also includes a position dependent gear controller operative to control the gear ratio of the reducing gearbox as a function of a vertical position of at least one of the first and second rescue platforms.  
         [0012]     In accordance with still another preferred embodiment of the present invention the dynamic resistance device also includes a visually sensible position indicator associated with the position dependent gear controller. Preferably, the dynamic resistance device also includes a mechanical brake assembly operative, when in a first position, to prevent vertical motion of the first and second rescue platforms. More preferably, the mechanical brake assembly also includes a handle which is selectably movable between the first position and a second position to enable a user to selectably operate the system. Additionally or alternatively, the mass rescue system also includes at least one buffer for final stopping of vertical motion of the first and second rescue platforms.  
         [0013]     There is also provided in accordance with a preferred embodiment of the present invention a method for mass rescue including providing upper and lower rotatable supports having at least one elongate flexible element wound thereabout, the at least one elongate flexible element having at least first and second rescue platforms mounted at locations therealong arranged with respect to the upper and lower rotatable supports such that downward motion of the first rescue platform produces concomitant upward motion of the second rescue platform and vice versa, providing dynamic resistance governing vertical motion of the at least one elongate flexible element with respect to the upper and lower rotatable supports and loading the first and second rescue platforms to different weights such that the first and second rescue platforms undergo upward and downward motion produced by gravitational acceleration and without requiring an external energy source.  
         [0014]     In accordance with a preferred embodiment of the present invention the method also includes providing at least one guiding element which is operative to guide the first and second rescue platforms and mounting the at least one guiding element onto a building. Preferably, the method also includes operating a brake assembly to enable vertical motion of at least one of the first and second rescue platforms. More preferably, the method also includes operating the brake assembly to stop at least one of the first and second rescue platforms at a selectable level.  
         [0015]     In accordance with another preferred embodiment of the present invention the method also includes prior to the providing a second rescue platform, providing at least one counter weight and loading the first platform to a lower weight than a weight of the counterweight such that downward gravitational motion of the counterweight results in upward motion of the first platform.  
         [0016]     There is additionally provided in accordance with another preferred embodiment of the present invention a mass rescue system including an upper rotatable support, a lower rotatable support disposed below the upper rotatable support, at least one elongate flexible element wound about the upper and lower rotatable supports and a first rescue platform and a counterweight mounted on the at least one elongate flexible element at locations therealong arranged with respect to the upper and lower rotatable supports such that downward motion of the first rescue platform produces concomitant upward motion of the counterweight and vice versa, the first rescue platform having a weight, when loaded to at least a first predetermined extent, which is greater than a weight of the counterweight and thus being operative to undergo downward motion produced by gravitational acceleration, causing concomitant upward motion of the counterweight, and the first rescue platform having a weight, when unloaded to at least a second predetermined extent, which is less than the weight of the counterweight and thus the counterweight is operative to undergo downward motion produced by gravitational acceleration, causing concomitant upward motion of the first rescue platform, when unloaded to at least a second predetermined extent.  
         [0017]     In accordance with a preferred embodiment of the present invention the counterweight includes at least a second rescue platform having a weight, when unloaded to at least a second predetermined extent, which is less than the weight of the first rescue platform, when loaded to at least a third predetermined extent and thus the counterweight is operative to undergo downward motion produced by gravitational acceleration, causing concomitant upward motion of the first rescue platform, when unloaded to at least a second predetermined extent.  
         [0018]     In accordance with another preferred embodiment of the present invention the mass rescue system also includes a dynamic resistance device operative to employ potential energy of the first rescue platform for braking downward motion thereof. Preferably, the at least one elongate flexible element includes at least one first elongate flexible element which is wound over the upper rotatable support and at least one second elongate flexible element which is wound under the lower rotatable support. Alternatively, the at least one elongate flexible element includes a looped elongate element.  
         [0019]     In accordance with yet another preferred embodiment of the present invention the mass rescue system also includes at least one guiding element, which is operative to guide the first rescue platform and the counterweight. Preferably, the at least one guiding element includes at least one rigid element. Alternatively, the at least one guiding element includes at least one elongate flexible element. More preferably, the first rescue platform includes a cabin.  
         [0020]     In accordance with still another preferred embodiment of the present invention the first rescue platform includes at least one guide assembly which rides along the at least one guiding element and which is operative to reduce transverse displacement of the first rescue platform. Additionally or alternatively, the first rescue platform also includes a safety assembly operative to prevent free-fall of the first rescue platform. Preferably, the mass rescue system also includes at least one stair unit associated with the first rescue platform.  
         [0021]     In accordance with a further preferred embodiment of the present invention the first rescue platform also includes at least one door and at least one door safety element operative to prevent vertical motion of the first rescue platform while the at least one door is open. Preferably, the first rescue platform also includes at least one of a first aid kit and a communications device. Additionally or alternatively, the dynamic resistance device is operative to slow vertical motion of the first rescue platform to a speed which is less than a predetermined speed.  
         [0022]     In accordance with yet a further preferred embodiment of the present invention the dynamic resistance device also includes a reducing gearbox and a fan descender which are operative to slow the vertical motion of the first rescue platform. Preferably, the dynamic resistance device also includes a position dependent gear controller operative to control the gear ratio of the reducing gearbox as a function of a vertical position of the first rescue platform. Additionally or alternatively, the dynamic resistance device also includes a visually sensible position indicator associated with the position dependent gear controller.  
         [0023]     In accordance with a still further preferred embodiment of the present invention the dynamic resistance device also includes a mechanical brake assembly operative, when in a first position, to prevent vertical motion of the first rescue platform. Preferably, the mechanical brake assembly also includes a handle which is selectably movable between the first position and a second position to enable a user to selectably operate the system. Additionally or alternatively, the mass rescue system also includes at least one buffer for final stopping of vertical motion of the first rescue platform.  
         [0024]     There is yet further provided in accordance with a further preferred embodiment of the present invention a method for mass rescue including providing upper and lower rotatable supports having at least one elongate flexible element wound thereabout, the at least one elongate flexible element having a first rescue platform and a counterweight mounted at locations therealong arranged with respect to the upper and lower rotatable supports such that downward motion of the first rescue platform produces concomitant upward motion of the counterweight and vice versa, providing dynamic resistance governing vertical motion of the at least one elongate flexible element with respect to the upper and lower rotatable supports and loading the first rescue platform to a first predetermined extent, such that it has a first weight which is greater than a weight of the counterweight, such that the first rescue platform undergoes downward motion produced by gravitational acceleration, causing concomitant upward motion of the counterweight and unloading the first rescue platform to at least a second predetermined extent, such that it has a second weight which is less than the weight of the counterweight and thus the counterweight is operative to undergo downward motion produced by gravitational acceleration, causing concomitant upward motion of the first rescue platform.  
         [0025]     In accordance with a preferred embodiment of the present invention the counterweight includes at least a second rescue platform having a weight, when unloaded to at least a second predetermined extent, which is less than the weight of the first rescue platform, when loaded to at least a third predetermined extent and thus the counterweight is operative to undergo downward motion produced by gravitational acceleration, causing concomitant upward motion of the first rescue platform, when unloaded to at least a second predetermined extent. Preferably, the method also includes providing at least one guiding element which is operative to guide the first rescue platform and mounting the at least one guiding element onto a building.  
         [0026]     In accordance with another preferred embodiment of the present invention the method also includes operating a brake assembly to enable vertical motion of the first rescue platform. Preferably, the method also includes operating the brake assembly to stop the first rescue platform at a selectable level.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0027]     The present invention will be understood and appreciated more fully from the following detailed description, taken in conjunction with the drawings in which:  
         [0028]      FIG. 1  is a simplified pictorial illustration of a mass rescue and evacuation system constructed and operative in accordance with a preferred embodiment of the present invention;  
         [0029]      FIGS. 2A and 2B  are simplified pictorial illustrations of top and bottom portions of the mass rescue and evacuation system of  FIG. 1 ;  
         [0030]      FIGS. 3A and 3B  are simplified pictorial illustrations of two embodiments of the mass rescue and evacuation system of  FIG. 1 , shown with and without stairs associated therewith;  
         [0031]      FIG. 4  is a simplified bottom view pictorial illustration of the mass rescue and evacuation system of  FIG. 3A  having a passenger cabin attached thereto;  
         [0032]      FIGS. 5A and 5B  are simplified pictorial illustrations of the passenger cabin which forms part of the mass rescue and evacuation system of  FIGS. 1-4 ;  
         [0033]      FIG. 6  is a simplified bottom view pictorial illustration of the mass rescue and evacuation system of  FIG. 4  having a fan-descender attached thereto;  
         [0034]      FIGS. 7A, 7B ,  7 C,  7 D,  7 E,  7 F and  7 G are simplified pictorial illustrations of typical use of the mass rescue and evacuation system of  FIGS. 1-6 ;  
         [0035]      FIG. 8  is a simplified illustration of an alternative embodiment of the mass rescue and evacuation system of the present invention;  
         [0036]      FIGS. 9A and 9B  illustrate two features of an alternative embodiment of the mass rescue and evacuation system of the present invention;  
         [0037]      FIG. 10  is a simplified top view illustrations of a further alternative embodiment of the present invention;  
         [0038]      FIGS. 11A and 11B  are two alternate simplified bottom portion front view illustrations of the embodiment of  FIG. 10 ; and  
         [0039]      FIG. 12  is a simplified pictorial illustration of yet another alternative embodiment of the present invention.  
     
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS  
       [0040]     Reference is now made to  FIG. 1 , which is a simplified pictorial illustration of a mass rescue and evacuation system constructed and operative in accordance with a preferred embodiment of the present invention and to  FIGS. 2A and 2B , which are simplified pictorial illustrations of top and bottom portions of the mass rescue and evacuation system of  FIG. 1 .  
         [0041]     As seen in  FIGS. 1-2B , the mass rescue and evacuation system is a passive, gravity-operated system and preferably includes top and bottom sheaves  100  and  102 . Preferably top sheave  100  is a deflection sheave, while bottom sheave is a traction and tension sheave. A pair of cabin mount assemblies, designated by reference numerals  104  and  106  are arranged for gravity-driven, generally vertical motion between sheaves  100  and  102  and are mounted on first and second cables  110  and  112 , which are wound over sheaves  100  and  102 . Cable  110 , known as a suspension cable, extends from the top of cabin mount assembly  104 , over deflection sheave  100  to the top of cabin mount assembly  106  and thus supports both cabin mount assemblies  104  and  106 . Cable  112 , known as a compensation cable, extends from the bottom of cabin mount assembly  104  under traction sheave  102  to the bottom of cabin mount assembly  106 .  
         [0042]     The cabin mount assemblies  104  and  106  each ride along a pair of generally vertical guiding rails, respectively designated by reference numerals  124  and  126 , which are mounted on vertically spaced brackets  128 , which are, in turn, fixed to a wall  130  of a building in spaced relationship therewith, by respective wall mounts  132 . As seen in  FIGS. 1-2B , when the mass rescue and evacuation system is not in use, cabins are not attached to cabin mount assemblies  104  and  106 , but a counterweight  140  is mounted on one of the cabin mount assemblies, here cabin mount assembly  106 , which is located at the top of the building, in order to provide initial, gravity-driven vertical motion of the system. It is appreciated that evacuation need not necessarily take place from the top of the building but rather may take place from any desired level or levels.  
         [0043]     Deflection sheave  100  is rotatably mounted on a generally horizontal axle  150  which is fixed onto an axle mount  152 . Axle mount  152 , is in turn mounted on a support element  154 , which in turn is mounted on a pair of guide rods  156 , which slidably extend through guide sockets  158 , which are fixedly mounted onto the uppermost rail mounting bracket  128 , here designated by reference numeral  160 . Support element  154  is in turn supported onto a manually vertically adjustable lifting jack  162 , which is mounted onto bracket  160  and provides selectably adjustable vertical positioning of deflection sheave  100 . Vertical adjustment of the mounting height of axle  150  takes place from time to time in order to compensate for natural cable elongation which takes place over time.  
         [0044]     Traction sheave  102  is mounted onto a lever arm  170 , which is pivotably mounted at one end thereof, designated by reference numeral  172  onto an anchored post  174 . An opposite end  176  of lever arm  170  is weighted by a static weight  178 , thus tensioning cables  110  and  112 , to an extent required for suitable traction between cable  112  and traction sheave  102 . A crankshaft  180  extends perpendicularly from a center of traction sheave  102  and is arranged for connection to a fan descender (not shown) as described hereinbelow with reference to  FIG. 6 .  
         [0045]     Turning particularly to the enlarged portion of  FIG. 2B , it is seen that the cabin mount assembly  104 , which is identical to cabin mount assembly  106  includes top and bottom roller guide assemblies, designated respectively by reference numerals  190  and  192 . The roller guide assemblies  190  and  192  enable the cabins (not shown) mounted onto cabin mount assemblies  104  and  106  to move vertically along guiding rails  124  and  126  at relatively high speed and with relatively low transverse displacement. Each roller guide assembly preferably includes a frame  200  onto which two sets  202 , each including three wheels  204 , are rotatably mounted.  
         [0046]     Each cabin mount assembly includes a pair of parallel spaced beams  210 , which are joined, inter alia by transverse elements  212  and  214  intermediate ends of the beams and by frame  200  at the bottoms of the beams  210 . At the top of each of beams  210  there is provided a transverse element  216 , which is additionally supported by a support  218 . Mounted onto each transverse element  216  is a cable connection side support element  220 . Fixedly attached to cable connection side support elements  220  is a suspension plate  222 , which is apertured to permit slidable passage therethrough of an anchor rod  224 . Below suspension plate  222 , a spring  226  is mounted about anchor rod  224  and is seated on a retaining disk  228 , which is fixed to a lower end of anchor rod  224  by nuts  230 . At an upper end of anchor rod  224  there is provided a wedge cable socket  232  which connects anchor rod  224  to cable  110 .  
         [0047]     Supported on transverse elements  216  is an anti-free fall safety assembly  234 . Assembly  234  preferably is identical or similar to a Model EB 75GS commercially available from Aufzugtechnologie G. Schlosser GmbH of Dachau, Germany.  
         [0048]     At a lower side of one of beams  210 , a bracket  236  mounted an anchor rod  238 , at an end of which there is provided a wedge cable socket  240  which connects anchor rod  238  to cable  112 .  
         [0049]     An entrance door safety latch  244 , which cooperates with an entrance door safety mechanism, described hereinbelow with reference to  FIGS. 5A and 5B , is preferably also mounted on one of beams  210 .  
         [0050]     The system as described hereinabove with reference to  FIGS. 1-2B  is in its non-deployed, ready operative orientation. Stair units  300 , as shown in  FIG. 3A  may be provided when the system is in its non-deployed operative orientation or may be moved into place when an emergency situation occurs. Alternatively stair units  300  may be obviated, as in the embodiment shown in  FIG. 3B .  
         [0051]     Normally, the cabins are not mounted onto the remainder of the system when the system is in its non-deployed operative orientation. Alternatively, one or both cabins may be mounted.  
         [0052]      FIG. 4  illustrates a cabin  400  mounted onto cabin mount assembly  104 . A pair of buffers  402 , such as Model ACLA 300403 commercially available from ACLA-WERKE GmbH of Cologne, Germany are also illustrated, one of which underlies and is engaged by cabin  400 .  
         [0053]     Reference is now made to  FIGS. 5A and 5B , which are simplified pictorial illustrations of cabin  400 , mounted onto cabin mount assembly  104 . As seen in  FIGS. 5A and 5B , the cabin  400  preferably comprises a floor  410  and enclosure walls  412  and  416  preferably arranged at right angles to each other. Opposite wall  412 , an exit door  418  is provided and is preferably configured as a swing door, swinging outwardly, as shown. An exit door safety device  420  is associated with exit door  418  and is operative to prevent upward vertical movement of the cabin when the exit door  418  is open. An additional exit door safety device  422  is associated with exit door  418  and prevents opening of exit door  418  except when the cabin is at a predetermined vertical position, suitable for egress of persons therefrom. Opposite wall  416  there is provided an entrance door  424 , preferably configured as a slidable folding door. Entrance door  424  is operative to be engaged by entrance door safety latch  244 .  
         [0054]     Entrance door safety latch  244  is coupled by a cable  426 , cooperating with rollers  428 , to a safety device  430 , such as a Model P.F.B. BP.2 commercially available from P.F.B. of Modena, Italy, which cooperates with a tension spring  432 . Safety device  430  selectably engages guide rail  124 , thus selectably locking the cabin  400  against downward vertical motion.  
         [0055]     In the operative orientation shown in  FIG. 5B , when the entrance door  424  is closed, latch  244  is in a generally horizontal orientation, locking the entrance door closed. In this generally horizontal orientation, latch  244 , via cable  426  releases safety device  430 , thereby permitting downward vertical displacement of the cabin  400 .  
         [0056]     When latch  244  is not in the generally horizontal orientation, it causes safety device  430  to engage the guide rail  124 , thus preventing downward motion of the cabin and permits opening of the entrance door  424 .  
         [0057]     It is appreciated that cabin  400  may be equipped with a first aid kit  426  and a communications unit  428 .  
         [0058]     Reference is now made to  FIG. 6 , which illustrates a fan descender assembly  500 . Fan descender assembly  500  preferably includes a shaft  502  to which is connected a crankshaft coupler  504  for connection to crankshaft  180 . Shaft  502  is coupled to a reducing gearbox  506 , typically having selectable gear ratios of 1:8 and 1:28. An output shaft of gearbox  506  is coupled to a fan  508 , preferably providing sufficient dynamic resistance to limit the speed of descent of a loaded cabin  400  under gravitational acceleration to 3.5 meters per second.  
         [0059]     Rotation of the shaft  502  is also coupled, preferably by a chain  520 , to an automatic vertical position dependent gear ratio controller  522 , which is operative, on the basis of the sensed rotation of the shaft  502  to determine the vertical position of the cabin  400  and to set the gear ratio accordingly. Thus, typically, when the loaded cabin  400  is lowered to a height of 10 meters above its intended landing position, the increased gear ratio is applied, thus reducing the speed of descent to a leveling speed of 1 meter per second. Preferably, associated with the gear ratio controller  522  is a mechanical visually sensible vertical position indicator  524 . The descending cabin  400  comes to a complete stop by engagement with buffer  402 . The height of the buffer  402  determines the exact level at which the cabins are stopped.  
         [0060]     The output shaft of gearbox  506  is also preferably coupled to a mechanical brake assembly  530 , which is normally locked, preventing vertical motion of the system. An authorized operator may operate a handle  532  of assembly  530 , typically moving it downward, to unlock the brake assembly  530  and thus enable operation of the system. The visually sensible vertical position indicator  524  may be employed by the authorized operator to move the brake handle  532  upward thereby to stop the cabin  400  at an intermediate level of the building, if desired.  
         [0061]     Reference is now made to  FIGS. 7A-7G , which are simplified pictorial illustrations of typical use of the mass rescue and evacuation system of  FIGS. 1-6 . Turning to  FIG. 7A , it is seen that a rescue person is entering cabin  400  via stairs  300  and that another rescue person is pulling downward on handle  532  to release brake assembly  530  and thereby permit operation of the mass rescue and evacuation system. Once brake assembly  530  is thus released, no further engagement with handle  532  is required throughout operation of the system, other than if it is wished to stop a cabin at a location intermediate its top and bottom locations. It is appreciated that the system of  FIGS. 1-6  can be employed to raise rescue personnel to any level of a building or other structure.  
         [0062]     Reference is now made to  FIG. 7B , which illustrates cabin  400  being raised by the weight of counterweight  140 . Vertical motion of the cabin begins only after door  418  is closed. It is appreciated that the weight of counterweight  140  is preferably greater than that of cabin  400  loaded with one or two rescue personnel and their equipment, so as to be able to provide raising of cabin  400  under gravitational acceleration and without requiring an external source of energy.  FIG. 7C  shows cabin  400  approaching the roof of the building, its rate of ascent being slowed by the fan descender assembly  500 .  
         [0063]      FIG. 7D  shows the cabin  400  at the roof of the building, the sliding entrance door  424  being opened by a rescue person and occupants of the building being ready for evacuation. It is noted that safety device  244  is in an activated state, thus preventing vertical motion of the cabin  400  so long as the door  424  is open.  FIG. 7E  shows loading of the cabin  400  by evacuees. Typically, the cabin  400  accommodates at least 10 persons and may accommodate wheelchair bound persons.  
         [0064]      FIG. 7F  shows that during loading of cabin  400 , while entrance door  424  is open, preferably the counterweight  140  is replaced by a second cabin  400 . Since the loaded cabin  400  weighs more than the empty or partially empty second cabin, once entrance door  424  is closed, the first cabin descends while the second cabin is raised correspondingly, and the system reaches the orientation shown in  FIG. 7G , at which the evacuees leave cabin  400  via exit door  418  and stairs  300  as shown.  
         [0065]     It is appreciated that the cabins  400  can be stopped at intermediate levels of the building by suitable operation of brake handle  532  by an authorized operator.  
         [0066]     Reference is now made to  FIG. 8 , which is a simplified illustration of an alternative embodiment of the mass rescue and evacuation system of the present invention. The embodiment of  FIG. 8  is similar to that of  FIGS. 1-7G , other than in that the a fan descender assembly  800  is located at the top of the mass rescue and evacuation system rather than at the bottom as in the embodiment of  FIGS. 1-7G . This is particularly suitable for enabling actuation of the system by an authorized person located within the building.  
         [0067]     In the embodiment of  FIG. 8 , the mass rescue and evacuation system is a passive, gravity-operated system and preferably includes a top sheave  801  and a bottom sheave (not shown). Preferably top sheave  801  is a traction sheave, while the bottom sheave is a tension sheave. A pair of cabin mount assemblies, designated by reference numerals  804  and  806  are arranged for gravity-driven, generally vertical motion between top sheave  801  and the bottom sheave and are mounted on first and second cables  810  and  812 , which are wound over the top sheave  801  and the bottom sheave.  
         [0068]     Cable  810 , known as a suspension cable, extends from the top of cabin mount assembly  804 , over traction sheave  801  to the top of cabin mount assembly  806  and thus supports both cabin mount assemblies  804  and  806 . Cable  812 , known as a compensation cable, extends from the bottom of cabin mount assembly  804  under the deflection sheave to the bottom of cabin mount assembly  806 .  
         [0069]     The cabin mount assemblies  804  and  806  each ride along a pair of generally vertical guiding rails, respectively designated by reference numerals  824  and  826 , which are mounted on vertically spaced brackets  828 , which are, in turn, fixed to a wall  830  of a building in spaced relationship therewith, by respective wall mounts (not shown). Typically, when the mass rescue and evacuation system is not in use, cabins are not attached to cabin mount assemblies  804  and  806 , but a counterweight  840  is mounted on one of the cabin mount assemblies, here cabin mount assembly  806 , which is located at the top of the building, in order to provide initial, gravity-driven vertical motion of the system. It is appreciated that evacuation need not necessarily take place from the top of the building but rather may take place from any desired level or levels.  
         [0070]     Traction sheave  801  is rotatably mounted on a generally horizontal axle  850  which is fixed onto an axle mount (not shown). The axle mount, is in turn mounted on a support element  854 , which in turn is mounted on a pair of guide rods  856 , which slidably extend through guide sockets (not shown), which are fixedly mounted onto the uppermost rail mounting bracket  828 , here designated by reference numeral  860 . Support element  854  is in turn supported onto a manually vertically adjustable lifting jack  862 , which is mounted onto bracket  860  and provides selectably adjustable vertical positioning of traction sheave  801 . Vertical adjustment of the mounting height of axle  850  takes place from time to time in order to compensate for natural cable elongation which takes place over time.  
         [0071]     The deflection sheave is mounted onto a lever arm  870 , which is pivotably mounted at one end thereof onto an anchored post  874 . An opposite end of lever arm  870  is weighted by a static weight (not shown), thus tensioning cables  810  and  812 , to an extent required for suitable traction between cable  810  and traction sheave  801 . A connection shaft  880  extends perpendicularly from a center of traction sheave  801  and is arranged for connection to fan descender assembly  800 .  
         [0072]     Stair units  882  may be provided when the system is in its non-deployed operative orientation or may be moved into place when an emergency situation occurs. Alternatively stair units  882  may be obviated, as in the embodiment shown in  FIG. 3B .  
         [0073]     Normally, cabins are not mounted onto the remainder of the system when the system is in its non-deployed operative orientation. Alternatively, one or both cabins may be mounted onto the system at all times.  FIG. 8  shows a cabin  884  mounted onto cabin mount assembly  804 . Cabin  884  may be similar in all relevant aspects to cabin  400  described hereinabove with reference to  FIGS. 5A and 5B . A pair of buffers  886  are also illustrated, one of which underlies and is engaged by cabin  884 .  
         [0074]     As explained above with reference to the embodiment of  FIGS. 1-7G , fan descender assembly  800  is operative to slow the descent of a loaded cabin  884  in response to gravitational acceleration to no more than a predetermined speed, preferably 3.5 meters per second.  
         [0075]     The fan descender assembly  800  includes a reducing gearbox  888 , typically having selectable gear ratios of 1:8 and 1:28. An output shaft of gearbox  888  is coupled to a fan  890 , preferably providing sufficient dynamic resistance to limit the speed of descent of the cabin  884  under gravitational acceleration to 3.5 meters per second.  
         [0076]     Rotation of the connection shaft  880  is also coupled, preferably by a chain  892 , to an automatic vertical position dependent gear ratio controller  894 , which is operative, on the basis of the sensed rotation of the shaft  880  to determine the vertical position of the cabin  884  and to set the gear ratio accordingly. Thus, typically, when the loaded cabin  884  is lowered to a height of 10 meters above its intended landing position, the increased gear ratio is applied, thus reducing the speed of descent to a leveling speed of 1 meter per second. Preferably, associated with the gear ratio controller  894  is a mechanical visually sensible vertical position indicator  896 . The descending cabin  400  comes to a complete stop by engagement with buffer  886 . The height of the buffer  886  determines the exact level at which the cabins are stopped.  
         [0077]     The output shaft of gearbox  888  is also preferably coupled to a mechanical brake assembly  898  which is normally locked, preventing vertical motion of the system. An authorized operator may operate a handle  899  of brake assembly  898 , typically moving it downward, to unlock the brake assembly  898  and thus enable operation of the system. The visually sensible vertical position indicator  896  may be employed by the authorized operator to move the brake handle  899  upward thereby to stop the cabin  884  at an intermediate level of the building, if desired.  
         [0078]     Reference is now made to  FIGS. 9A and 9B , which illustrate two features of an alternative embodiment of the mass rescue and evacuation system of the present invention. The embodiment of  FIGS. 9A and 9B  is similar to the embodiment of  FIGS. 1-7G  other than in the arrangement of the guiding rails. Whereas in the embodiment of  FIGS. 1-7G , all four of the guiding rails  124  and  126  ( FIGS. 1-2B ) are mounted on brackets  128 , in the embodiment of  FIGS. 9A and 9B , rails  900  and  902  are mounted on the same brackets  928 , while rails  930  and  932  are mounted, each on respective separate brackets  940  and  942  and are spaced from corresponding rails  930  and  932  by a distance slightly larger than the width of a cabin, such that each cabin is guided on each of its sides by a rail. This embodiment is particularly suitable for use with relatively large cabins, such as those which can accommodate up to approximately 100 people.  
         [0079]     It is appreciated that the embodiment of  FIG. 9A  preferably employs a double-wrap cable winding arrangement about the traction sheave  950 , as shown in  FIG. 9B , thereby to increase the traction between a cable  952  and the traction sheave  950 . This enables relatively large loads to be accommodated at relatively high vertical speeds.  
         [0080]     As seen in  FIG. 9B , the double-wrap cable winding arrangement provides winding of cable  952  initially about traction sheave  950 , then about a deflection sheave  954  and then again about traction sheave  950 .  
         [0081]     In the embodiment of  FIGS. 9A and 9B , the mass rescue and evacuation system is a passive, gravity-operated system and preferably includes a top sheave (not shown) which is a deflection sheave and bottom sheaves  950  and  954 . A pair of cabin mount assemblies, designated by reference numerals  956  and  958  is arranged for supporting each of two cabins, respectively designated by reference numerals  960  and  962 .  
         [0082]     Cabins  960  and  962  are arranged for gravity-driven, generally vertical motion and are mounted on a first cable  964  and a second cable  952 , which is wound in a double-wrap arrangement over sheaves  950  and  954 , as described hereinabove. First cable  964 , known as a suspension cable, extends from the top of cabin  960 , over the top sheave to the top of cabin  962  and thus supports both cabins  960  and  962 . Cable  952 , known as a traction cable, extends from the bottom of cabin  960  in a double-wrap arrangement about sheaves  950  and  954  to the bottom of cabin  962 .  
         [0083]     The cabin mount assemblies  956  and  958  of cabin  960  ride along respective guiding rails  900  and  930 , while cabin mount assemblies  956  and  958  of cabin  962  ride along respective guiding rails  902  and  932 . Typically, when the mass rescue and evacuation system is not in use, cabins  960  and  962  are not attached to the remainder of the mass rescue and evacuation system, but a counterweight (not shown) is mounted on one of the cabin mount assemblies, which is located at the top of the building, in order to provide initial, gravity-driven vertical motion of the system. It is appreciated that evacuation need not necessarily take place from the top of the building but rather may take place from any desired level or levels.  
         [0084]     Traction sheave  950  is mounted onto a lever arm  970 , which is pivotably mounted at one end thereof, designated by reference numeral  972  onto an anchored post  974 . An opposite end  976  of lever arm  970  is weighted by a static weight  978 , thus tensioning cables  952  and  964 , to an extent required for suitable traction between cable  952  and traction sheave  950 . A connection shaft (not shown) extends perpendicularly from a center of traction sheave  950  and is arranged for connection to a fan descender assembly (not shown).  
         [0085]     Stair units (not shown) may be provided when the system is in its non-deployed operative orientation or may be moved into place when an emergency situation occurs. Alternatively the stair units may be obviated, as in the embodiment shown in  FIG. 3B .  
         [0086]     Normally, cabins are not mounted onto the remainder of the system when the system is in its non-deployed operative orientation. Alternatively, one or both cabins may be mounted onto the system at all times.  FIG. 9A  shows cabins  960  and  962  mounted onto cabin mount assemblies  956  and  958 . Cabins  960  and  962  may be similar in all relevant aspects to cabin  400  described hereinabove with reference to  FIGS. 5A and 5B .  
         [0087]     As explained above with reference to the embodiment of  FIGS. 1-7G , the fan descender assembly (not shown) is operative to slow the descent of a loaded cabin in response to gravitational acceleration to no more than a predetermined speed, preferably 3.5 meters per second. The fan descender assembly may be similar to the fan descender assemblies described hereinabove.  
         [0088]     Reference is now made to  FIGS. 10, 11A  and  11 B, which illustrate a further alternative embodiment of the present invention. As seen in  FIG. 10A , the embodiment of  FIGS. 10-11B  is similar to that shown in  FIG. 9A  other than in that the guide rails  900 ,  902 ,  930  and  932  are replaced by tensioned guide wires  1000 ,  1002 ,  1030  and  1032 . The guide wires are engaged by slidable guiding shoes  1040  mounted on cabin mount assemblies arranged at the sides of the cabins.  
         [0089]     Due to the replacement of rails by tensioned cables, a balancing type of cable tensioning arrangement is preferably provided.  FIG. 11A  shows a suitable double-wrap cable winding arrangement for a system wherein a fan descender assembly is located at the bottom of the mass rescue and evacuation system. As seen in  FIG. 11A , a traction cable  1152  is wound first about a traction sheave  1154 , then wound about a deflection sheave  1156  and again wound about traction sheave  1154  and again wound about deflection sheave  1156 .  
         [0090]     Deflection sheave  1156  is rotatably mounted at a fixed location. Traction sheave  1154  is mounted onto lever arm  1160  which is pivotably mounted at one end thereof, designated by reference numeral  1162  onto an anchored post  1164 . An opposite end  1166  of lever arm  1160  is weighted by a static weight  1168 , thus tensioning cable  1152  to an extent required for suitable traction between cable  1152  and sheaves  1154  and  1156 .  
         [0091]      FIG. 11B  shows a suitable cable winding arrangement for a system wherein the fan descender assembly is located at the top of the mass rescue and evacuation system. As seen in  FIG. 11B , a tension cable  1172  is wound first about a first deflection sheave  1174  and then wound about a second deflection sheave  1176 .  
         [0092]     Deflection sheaves  1174  and  1176  are each rotatably mounted in mutually spaced positions onto a mounting beam  1177 , which is weighted by a static weight  1178 , thus tensioning cable  1172  to an extent required for suitable traction between cable  1172  and sheaves  1174  and  1176 .  
         [0093]     In the embodiments of  FIGS. 10-11B , the mass rescue and evacuation system is a passive, gravity-operated system and preferably includes top sheaves (not shown) and bottom sheaves  1154  &amp;  1156  or  1174  &amp;  1176 . A pair of cabin mount assemblies, designated by reference numerals  1180  and  1182 , is arranged for supporting each of two cabins, respectively designated by reference numerals  1184  and  1186 .  
         [0094]     Cabins  1184  and  1186  are arranged for gravity-driven, generally vertical motion and are mounted on a traction cable and a tension cable.  
         [0095]     In the embodiment of  FIG. 11A , where the fan descender assembly is located at the bottom, the traction cable is at the bottom and indicated as traction cable  1152  which is wound in a double-wrap arrangement over sheaves  1154  and  1156 , as described hereinabove.  
         [0096]     In the embodiment of  FIG. 11B , where the fan descender assembly is located at the top, the traction cable is at the top and tension cable  1172  is at the bottom and is wound over sheaves  1174  and  1176 , as described hereinabove.  
         [0097]     In both embodiments, a top cable  1188  extends from the top of cabin  1184 , over the top sheave to the top of cabin  1186  and thus supports both cabins  1184  and  1186 .  
         [0098]     The cabin mount assemblies  1180  and  1182  of cabin  1184  ride along respective tensioned guide wires  1000  and  1030 , while cabin mount assemblies  1180  and  1182  of cabin  1186  ride along respective tensioned guiding wires  1002  and  1032 . Typically, when the mass rescue and evacuation system is not in use, cabins  1184  and  1186  are not attached to the remainder of the mass rescue and evacuation system, but a counterweight (not shown) is mounted on one of the cabin mount assemblies, which is located at the top of the building, in order to provide initial, gravity-driven vertical motion of the system. It is appreciated that evacuation need not necessarily take place from the top of the building but rather may take place from any desired level or levels.  
         [0099]     Stair units (not shown) may be provided when the system is in its non-deployed operative orientation or may be moved into place when an emergency situation occurs. Alternatively the stair units may be obviated, as in the embodiment shown in  FIG. 3B .  
         [0100]     As explained above with reference to the embodiment of  FIGS. 1-7G , the fan descender assembly (not shown) is operative to slow the descent of a loaded cabin in response to gravitational acceleration to no more than a predetermined speed, preferably 3.5 meters per second. The fan descender assembly may be similar to the fan descender assemblies described hereinabove.  
         [0101]     Reference is now made to  FIG. 12 , which is a simplified pictorial illustration of yet another alternative embodiment of the present invention. In the embodiment of  FIG. 12 , which has various similarities to features in the embodiments of  FIGS. 1-11 , an inclined cabin travel path is provided, so as to quickly distance a descending cabin from the building. In the embodiment of  FIG. 12 , cabins  1200  are suspending from a tensioned looped cable  1202  as shown.  
         [0102]     In the embodiment of  FIG. 12 , the mass rescue and evacuation system is a passive, gravity-operated system and preferably includes top and bottom pairs of sheaves  1204  and  1206 . Preferably top sheaves  1204  are traction sheaves, while bottom sheaves  1206  are tension sheaves. A pair of cabin suspension assemblies, designated by reference numerals  1208  and  1210  are arranged for gravity-driven, inclined vertical motion between pairs of sheaves  1204  and  1206  and are mounted on tensioned looped cable  1202 , which is wound over pairs of sheaves  1204  and  1206 . Cabin suspension assemblies  1208  and  1210  may be of the type used conventionally in cable cars.  
         [0103]     Typically, when the mass rescue and evacuation system is not in use, cabins are not attached to cabin mount assemblies  1208  and  1210 , but a counterweight (not shown) is mounted on one of the cabin mount assemblies, which is located at the top of the building, in order to provide initial, gravity-driven vertical motion of the system. It is appreciated that evacuation need not necessarily take place from the top of the building but rather may take place from any desired level or levels.  
         [0104]     Traction sheaves  1204  are rotatably mounted in fixed mutually spaced positions on a frame  1212  and looped cable  1202  is double wrapped about traction sheaves  1204 .  
         [0105]     Deflection sheaves  1206  are rotatably mounted in fixed mutually spaced position onto a beam  1214 , which is in turn mounted in a selectably tensionable manner to an anchor  1216 , thus tensioning looped cable  1202  to an extent required for suitable traction between cable  1202  and traction sheaves  1204 . A connection shaft  1217  extends perpendicularly from a center of a traction sheave  1204  and is arranged for connection to a fan descender assembly  1218 .  
         [0106]     As explained above with reference to the embodiment of  FIGS. 1-7G , fan descender assembly  1218  is operative to slow the descent of a loaded cabin  1200  in response to gravitational acceleration to no more than a predetermined speed, preferably 3.5 meters per second.  
         [0107]     The fan descender assembly  1218  includes a reducing gearbox  1220 , typically having selectable gear ratios of 1:8 and 1:28. An output shaft of gearbox  1220  is coupled to a fan  1222 , preferably providing sufficient dynamic resistance to limit the speed of descent of the cabin  1200  under gravitational acceleration to 3.5 meters per second.  
         [0108]     Rotation of the connection shaft  1217  is also coupled, preferably by a chain  1224 , to an automatic vertical position dependent gear ratio controller  1226 , which is operative, on the basis of the sensed rotation of the shaft  1217  to determine the vertical position of the cabin  1200  and to set the gear ratio accordingly. Thus, typically, when the loaded cabin  1200  is lowered to a height of 10 meters above its intended landing position, the increased gear ratio is applied, thus reducing the speed of descent to a leveling speed of 1 meter per second. Preferably, associated with the gear ratio controller  1226  is a mechanical visually sensible vertical position indicator  1228 .  
         [0109]     The output shaft of gearbox  1220  is also preferably coupled to a mechanical brake assembly  1230  which is normally locked, preventing vertical motion of the system. An authorized operator may operate a handle  1232  of brake assembly  1230 , typically moving it downward, to unlock the brake assembly  1230  and thus enable operation of the system.  
         [0110]     It is appreciated that in the various embodiments of the present invention, multiple suspension and compensation cables may be provided in place of single cables, as appropriate.  
         [0111]     It is also appreciated that multiple mass rescue and evacuation systems may be mounted on a given building and may be of differing configurations depending on the physical features of the building and other requirements. The provision of multiple mass rescue and evacuation systems enables evacuation from alternative exit locations in the building.  
         [0112]     It is appreciated that although many of the embodiments described hereinabove are at least partially assembled at the time of deployment, alternatively, the mass rescue and evacuation system may be fully assembled and ready to use at all times. In such a case, a counterweight is preferably incorporated in the upper cabin and preferably is arranged to be removable when that cabin reaches its lower position.  
         [0113]     It will be appreciated by persons skilled in the art that the present invention is not limited to what has been particularly shown and described hereinabove. Rather the present invention includes both combinations and subcombinations of the features described hereinabove as well as modifications and variations which would occur to persons skilled in the art upon reading the foregoing description and which are not in the prior art.