Patent Application
20150136525
An embodiment of the invention is generally related to raising firefighters and equipment to, and evacuation of people from, the upper floors of a multi-story building during an emergency such as a fire. Other embodiments are also described.
When an emergency or disaster situation occurs in a tall structure such as a multi-story building, emergency personnel (such as firefighters and paramedics) are called to alleviate the disaster or rescue people trapped in the building. Nowhere has this been more horribly exemplified than at the World Trade Center towers in New York City, on Sep. 11, 2001. In that case, people were trapped in the upper floors of the buildings because of fires raging in lower floors. In addition, the emergency stairwells had become filled with smoke and hazardous gasses or had been rendered completely impassible due to debris. Although there were also people on floors below the fires, some of them might not have been able to walk down the emergency stairwell because they were injured. In short, there was a need for massive evacuation from and assistance to all of these upper floors. The term “upper floors” here is intended to mean those portions of a multi-story building that are above a base (e.g., the ground floor) of the building.
Because most of the upper floors were too high to be accessed from outside of the building using conventional firefighter ladders, emergency personnel had to walk up hundreds of flights of stairs (elevators are typically automatically shut down when there is a building fire). To make things worse, they had to battle the heat and smoke on the way up through the stairs, while carrying relatively heavy equipment such as oxygen bottles, medical kits, and other equipment needed to alleviate the disaster or assist the injured. Their progress up the stairs unfortunately was too slow in view of the rate at which the fires were consuming the building. Some of the emergency personnel may even have suffered heart attacks or smoke inhalation injuries while climbing the numerous stairs. It is possible that some of the evacuees, particularly those in the top most floors near the roof, might have been rescued from the building by an emergency helicopter that could land on the roof. However, this would still leave a significant number of people with no choice but to jump out of a window of the building to their deaths, rather than be burned alive or asphyxiated by the raging fires.
There have been several systems disclosed for use in rescuing persons trapped in the upper floors of a multi-story building. See, e.g. U.S. Pat. Nos. 4,209,077; 4,919,228; 4,355,699; 4,424,884; and 4,406,351. Some of these systems use a platform or gondola that is suspended alongside an exterior face of the building by a cable. The platform is raised or lowered to a desired location next to an upper floor. Persons are then evacuated from that floor, and the platform loaded with the evacuees is then lowered to a safe haven (typically on the ground next to the building). However, these systems might suffer from a number of problems, including a relatively high cost of manufacture or maintenance as well as complex operation.
The embodiments of the invention are illustrated by way of example and not by way of limitation in the figures of the accompanying drawings in which like references indicate similar elements. It should be noted that references to “an” embodiment of the invention in this disclosure are not necessarily to the same embodiment, and they mean at least one.
According to an embodiment of the invention, a system and method are described for reaching from outside an upper floor of a multi-story building, that is believed to be more cost efficient and effective. This system may include a closed loop of cable that is installed around a pulley which is located at a roof or somewhere above an upper floor of the building. The loop is at least long enough to reach an area next to a base of the building (when allowed to hang outside of the building). The loop is to be installed into a winch preferably located in the area next to the base of the building. The loop of cable is preferably of such length as to render both a far portion and a near portion of the loop (relative to the building) under tension once the loop has been properly installed into the winch and the winch has been correctly located relative to the building. In operation, a load is attached to the loop in the area next to the base of the building. Then, the winch is activated to raise the attached load until it has reached and is suspended at a desired level that is near the same level as an upper floor of the building.
While the load is suspended by the installed loop, the load may be moved closer or farther to the building, by any one of several techniques. For example, the winch may be moved either upwards or towards the building, to position the suspended load closer to the building for easier access into or from the building. This may be done by moving a vehicle at the base of the building, and to which the winch is anchored, horizontally closer to the building. Alternatively, the winch may be moved upward relative to the vehicle, while the vehicle remains still. Yet another alternative is to cause one or more moveable pulleys around which the loop is installed to move, while keeping the winch inactive and still, to release some slack in the loop and thereby allow the suspended load to move closer to the building. Other ways of changing the tension in the near portion of the loop below the load may alternatively be used to decrease the tension and thereby move the suspended load closer to the building.
The load may include a container, such that people or objects may be taken from the upper floor by being accepted into the container (while the container is suspended at approximately the upper floor). Once the container has been loaded, it may be moved away from the building, prior to lowering the people or objects to a haven (e.g., the area next to the base of the building) by activating the winch in its opposite direction. For example, the winch may be moved either downwards or away from the building, to back the suspended load away from the building. This may be done by moving the vehicle at the base of the building, to which the winch is anchored, horizontally further from the building. Alternatively, the winch may be moved downward relative to the vehicle, while the vehicle remains still. Yet another alternative is to cause one or more moveable pulleys around which the loop is installed to move, while keeping the winch inactive and still, to take up slack in the loop and thereby pull the suspended load farther away from the building. Other ways of changing the tension in the near portion of the loop below the suspended load may alternatively be used to perhaps increase the tension and thereby move the suspended load farther from the building.
One or more of the embodiments of the invention described here may also be used to effectively and quickly raise various types of emergency equipment, such as fire fighting equipment, air and water hoses, heavy equipment and emergency electric power, to the upper floors of the building. As a result, firefighters need no longer carry them up a stairwell of the building. This also helps reduce traffic congestion and load on the stairwell, while at the same time providing more fire fighting equipment to the disaster site.
Although the system is expected to be particularly useful for moving firefighters and equipment upward, and evacuating occupants from relatively high building levels that are beyond the reach of ladder trucks, the system may also prove to be useful for lower height buildings (and particularly those without sprinkler systems). That is because it may have the capability to lift and lower larger loads than can existing ladder systems. In addition, evacuees and awkward or large objects may be handled much easier than on a ladder. Disabled persons and hospital patients may also find it easier to use a container basket or gondola, rather than a ladder.
The logistics of certain embodiments are relatively straight forward yet adaptable. For instance, a relatively low installation cost is incurred by the building owner, primarily due to the pulley (and its attachments to the building) and the loop of cable. The winch is preferably to be mounted on conventional Fire Department vehicles or a standard truck. In addition, there is also the benefit of being able to use the system to hoist and deposit non-emergency equipment to any upper floor (which may not be practical using the built-in elevator system of the building). There may be additional advantages or benefits to using the system, including some that will be further discussed below.
Referring to
A pulley 22 is mounted, in this embodiment, on the roof 502 near the edge 504. An alternative would be to attach the pulley to somewhere on the building above an upper floor. The distance between the pulley 22 and the base 506, along a vertical, is, in this case, the building height, H. The pulley may be permanently attached to a structural support of the building located near an edge of a roof of the building. Various ways of attaching the pulley to the building will be described below.
The system 20 also has a winch 24 which is preferably disposed in an area next to the base 506 of the building, as shown. The winch 24 may alternatively be located near the top of the building (instead of near the bottom) with the pulley near the bottom. Upon activation (e.g., the application of motor power), the winch 24 can selectively rotate in a first direction or an opposite second direction. In a preferred embodiment, the winch 24 is anchored or secured to a vehicle 26 as shown, which may be a heavy, Fire Department truck such as a pumper, that is horizontally moveable toward and away from the building 500. Alternatively, the winch 24 may be moved horizontally and vertically in other ways, such as on a track, or vertically raised by a cylinder, a scissors lift or a boom that can be raised. For instance, such a track might be located on an adjacent building or structure, instead of on the ground as shown. As will be explained below, a reason for making the winch horizontally or vertically moveable is to allow a suspended load in the system to be moved a) away from a side of a building for clearance while being raised or lowered, and b) closer to the building for easier loading and unloading from the upper floor. There are several other ways of adjusting the tension on the loop for moving the suspended load towards and away from the side of the building. They include, for example, the embodiments of the invention depicted in
The system also features a closed loop of cable 28 that is connected around the pulley 22 and the winch 24. The cable may be a wire rope, rope, chain, line, or the like, which is of sufficient strength to suspend the intended load that will be attached to the cable, e.g. emergency personnel and equipment. The loop of cable 28 is of sufficient length so as to reach, when deployed outside of the building as shown, below the pulley to where emergency personnel gather in an area next to the base 506 of the building when responding to a disaster situation in the building. For example, the total length of the closed loop may be about twice the building height H for the embodiment of
The system 20 shown in
In
To move the load away from the side 508 of the building, the winch 24 may be moved outward to distance D2. The distance L increases while the height of the upper pulley 22 remains constant. In addition, the slack in the near portion 31 of the loop 28 is reduced, and has been moved to an angle large enough with respect to the side 508 that the container 30 is pulled clear of the building. This may help prevent the suspended container from striking the side 508, as the container 30 is lowered. The position of the winch 24 with respect to the building may accordingly be adjusted as needed, to not only adjust the tension in the near portion 31 of the loop of cable 28 but also to move any load that is suspended by the loop of cable towards or away from the side of the building. Note that the suspended container 30 may swing a little higher or lower (on an arc) as the distance L changes (even if the winch 24 were not turning).
The overall length of the loop cable 28 should be designed so as to allow for reasonable distances D1 and D2 to fall within an area next to the base 506 of the building that preferably can be easily accessed by emergency equipment and personnel when responding to a disaster situation in the building 500. However, an alternative to having the winch 24 move horizontally to adjust loop tension and horizontal load position is to provide for its vertical movement (or some combination of both). For example, the winch 24 could be installed on a short, elevator-type mechanism. Other alternatives that can increase or decrease the tension in the tail line, from below the suspended load to the winch, to thereby change the horizontal position of the suspended load with respect to the side 508 of the building, may also be used.
The vehicle 26 may also be equipped with an anchor feature to keep the vehicle (and hence the winch 24) fixed in a single location despite the forces generated while the loop of cable has been installed and is under tension. One example is to rigidly attach the vehicle to a lamp post or other relatively immovable structure; another may be to tie the vehicle in several different directions to respective anchor rings built into the area next to the base of the building.
Turning now to
Note that in this example, the deflector pulley 42 is rigidly attached to the backbone 35. An alternative here is to rigidly attach the deflector pulley 42 directly to the container body 33. The backbone 35, being pivotally attached at one end to the container body 33, helps stabilize and allows the container body to stay level. Also, to close the loop, the other end 40 of the cable in this embodiment is secured to the container body 33, via a snap hook. Alternative securing mechanisms are, of course, possible.
The embodiment of
Turning now to
In addition, the system also has a moveable or adjuster pulley 466. The adjuster pulley 466 in this embodiment is “floating” in that it need not be held other than by tension in the loop of cable 468 and an adjustment cable 474. In this embodiment, the adjuster pulley 466 is floating, while all other pulleys in the system as shown (pulleys 462, 464, 465, 467, and 472) remain fixed. Tension in the loop of cable 468, and in particular in the near portion 31 below the suspended container 30, may be adjusted by a drum winch 470. The drum winch 470 rotates, to alternatively pull and let out the adjustment cable 474. The adjustment cable 474 is installed around the drum winch 470 at one end, is connected to the adjuster pulley 466 at another end, and is installed around the pulley 472. Note that both the drum winch 470 and the traction winch 464 may be operated at the same time, to position the suspended container appropriately.
While the adjuster pulley 466 is floating, the pulley 472 is preferably permanently secured to the building 500 near its base as shown. On the other hand, the traction pulley 464, as well as the deflector pulleys 465 and 467, along with the drum winch 470, may be secured to a vehicle (e.g., a Fire Department truck), not shown, that will arrive at the scene in the area next to the base of the building 500 in the event of an emergency situation involving the building. The same vehicle may also be used to deliver the adjuster pulley 466, as well as perhaps the pulley 472. An operator of the system (such as an emergency worker) may control the raising and lifting of the suspended container 30 by activating the traction pulley 464 in one of its two opposite directions, and may also move the suspended container 30 towards and away from the side of the building 500 by activating the drum winch 470 in one of its opposite directions of rotation. Note that the diagram is not to scale, and is merely being used to illustrate the operation of the system. In practice, the relative size, location, and number of pulleys 465, 466, 467, and 472 may be different than shown.
Turning now to
Note that sometimes, even during the lifting process, winch B need not be turning in the same direction as winch A. Winch B should be operated to keep a relatively light tension in the tail section 31. If the tension is lowered (by winch B turning, when viewed in the angle shown in
While raising and lowering the attached load, both winches A and B (assuming they are of the same diameter) may be turning at the same speed, in the same direction. If any one of the winches is then stopped (e.g., because the load has reached a desired vertical position), the other may continue to run in either direction, to accurately locate the suspended load up or down (vertically) and in or out (horizontally relative to the building).
The intermediate section 330 of the cable, that may collect between the two winches, may be taken up and lifted clear of the bed of the vehicle 26, using, for example, a mechanism as shown in
As mentioned above, the top or upper pulley 22 may be permanently attached to a structural support of the building 500, and located in a single position near an edge 504 of the roof 502. This arrangement may be modified as shown in
Referring now to
In operation (114), a tail section of the cable, that runs between another end of the loop of cable and the winch, is led around a deflector pulley. This deflector pulley preferably is designed to move with the attached load, as the attached load is lowered and raised through operation of the winch. A mechanism that keeps the distance between the deflector pulley and the attached load substantially fixed, while the load is raised and lowered, may be used (e.g., affixing the deflector pulley to a backbone that in turn is secured to the container body.)
The other end of the loop of cable is attached to a traveler (115), e.g. via a snap hook mechanism. The traveler includes a roller that is to be positioned to ride along the hoist section of the loop. The traveler may have a hinged side that opens, allowing the hoist section of the cable to be placed inside.
Next, the winch may be moved horizontally or vertically, to place the closed loop under tension (116). As an alternative, the winch may be kept still while moving one or more adjuster pulleys. An example is shown in
Operation proceeds with activating the winch to raise the attached load (including, for example, emergency equipment and/or personnel loaded into a container at the base of the building) to an upper floor of the building. The winch is stopped when the load has reached a desired level, e.g. near that of a desired upper floor (124). The winch may then be moved to reduce tension in the loop, thereby causing the suspended load to approach the side of the building and, if desired, eventually touch and lie against the side (128). As explained above, other ways of reducing tension in the loop (to move the suspended load towards the building) may alternatively be used, e.g. see
Next, referring now to
The above described operations 124-144 may be repeated to access additional, upper floors of the building as needed. When finished with use of the system, the winch and/or adjuster pulley may be moved to untension the loop (152) followed by removal of the loop from the winch (156) and detaching any remaining load from the now loose loop (148). The winch may then be transported back to a storage or maintenance location, such as a Fire Department station (160). Finally, the loop of cable may be put away, by, for example, being reeled back up into its housing on the roof or secured to the side of the building (164).
Although the operations of the flow diagram above were described sequentially, that does not mean that the operations in all cases must be performed sequentially. For example, in operations 112-115, the loop may be closed (if not already closed) prior to, rather than after, installing the loop into the winch. As another example, the remaining load may be detached from the loop after removing the loop from the winch (operations 148 and 156). To affect such variations, it may be necessary to design the load and the manner in which the load is attached to the loop, or how the loop is closed, differently than shown in the figures.
The various embodiments of the invention described above allow access to an upper floor of a multi-story building from outside, without the need for an enclosure shaft or guide rails used by typical freight elevators. There are different types of containers that can be attached to the loop of cable of this system. They may be completely rigid, cage like structures, or may be composed of a platform with a flexible net. The portability of the containers, however, should be considered as a factor that affects their design. In particular, more than one container may need to be delivered, to the building, together with the winch. Alternatively, the containers may be stored at the building site rather than transported to the building. In addition, the container should preferably allow quick entry and exit by people. Also, if building projections are expected to keep the container from reaching the face of the building (even after the container has been moved as close as possible towards the building), some type of walkway to the container should be provided, for example, integrated with the container. Closeable entrances to the container are also desirable.
As described below, the loop of cable may be provided with a lifting ring to which the top of the container may be attached via a safety hook. This will allow the container to swing freely while suspended, depending upon the length of the line that attaches the hook to the top of the main structure of the container. Some movement is desirable, to help in manually positioning the container for loading and unloading. As an alternative to a top connection, the attachment line may be directly attached to a floor of the container. In that case, the container should be steadied at its top by the tension in the loop of cable that is hoisting the container. Although not shown in the figures, wheels should be fitted to the bottom of the container, preferably with brakes, for ease of movement when on the ground.
The container may also be designed to carry extension ladders, grappling hooks, crowd control equipment, cameras, batteries, generators, pumps, litters, harnesses, saws, and cutters.
The preferred type of cable to use is wire rope (e.g., multiple, flexible wires) whose size and type should be selected based upon the load capacity and traction design of the system, as well as the structural capacity of the pulley. While larger rope diameters can handle larger loads, smaller diameter wire ropes are, in general, easier to handle, less expensive, and require smaller pulleys. As an example, the wire rope diameter may be expected to be between ⅜ inch with a breaking strength of about 15,000 lbs., and ½ inch with a breaking strength of about 26,000 lbs. When used for rescue purposes, such as by the Fire Department, all instances of the system should preferably use the same, pre-selected wire rope size. Of course, these are only example dimensions such that in practice different dimensions may alternatively be used as appropriate.
The loop of wire rope should be draped over the top pulley, and should be long enough to reach an area next to the base of the building. For example, in the case of a single pulley embodiment, the length of the loop may be twice the vertical distance between the pulley and the base, plus about 10% height to allow the loads to be moved clear of the building, as was described above.
The winch may be a traction hoist that uses power and braking to directly act upon the far section of the loop, where power is used to pull in the far section and thereby lift a load that is attached to the near section, and braking is used to let out the far section to thereby lower the load. Where loads are attached to both the far and near portions of the loop, the winch should have both forward and reverse traction to power the lifting and lowering of the heavier container. The following description of the power requirements for the winch is provided in the context of an example, where a single container being a basket is provided with a combined load of the basket and its contents of 5,000 lbs., to travel upward at 500 feet per minute. The theoretical power requirement in this case is estimated to be 75 horsepower. If total system efficiency is estimated at fifty percent, for a hydraulically driven system, the power requirement would be 150 horsepower. Of course, reducing the specification to 250 feet per minute and 2,500 lbs. would reduce the needed horsepower to less than 40 horsepower. By using variable volume hydraulic drives, the system may be able to raise heavier loads at slower speeds and light loads at full speed. With adequate braking available, heavy loads may be lowered at the desired speed independent of the horsepower of the system. Depending on how the winch is transported (e.g., it may be anchored to and carried by an emergency response truck), the system could be driven from a power takeoff on the same vehicle as the one to which the winch is anchored (e.g., pumper), or from a separate Fire Department engine or trailer that arrives on the scene.
As an alternative to a hydraulic system, a modified, electric elevator drive system powered by a connection to an electrical grid (to also supply breaking power) may be used. Note that both hydraulic and electric drives are expected to have an inherent ability to provide speed control, as well as power for lifting and braking for lowering the loads.
Several techniques may be used for providing traction to raise and lower the load on the cable. The preferred technique is to create the traction by using a pressure roller whose force is generated by the tension created by the suspended load.
Note that the winch may be composed of a traction sheave (not shown) that lies flat, i.e. horizontal with a truck bed of the vehicle 26, see
The winch, which may be part of a control unit (not shown) for the entire system, may be placed at any location near the building that can be reached by, for example, the Fire Department. The winch may be placed in line with the pulley, at a right angle from the face of the building (
The containers that are attached to the cable are to travel up and down, preferably between the pulley at the top and the winch below. These containers, with their connections to the cable, need not pass over the pulley or under the winch. Accordingly, secure connections of most types may be used at the appropriate selected positions on the cable, without clearance concerns.
The cable may be cut to a single, continuous piece having a length that is twice the distance from the pulley to the designated position of the winch (e.g., at the base of the building). A ring may be attached at one end of the cut cable, and a snap hook at the other end can be used to connect the two ends to form a closed loop. The ring and snap hook may be assembled to the cable with thimbles. The ring also provides a secure attachment for hanging the container (or other load) to the cable.
As an alternative, the loop of cable may be formed of two separate, continuous pieces, each of a length that is one-half the distance between the pulley and the operating position of the winch at the base of the building, with similar ring and hook assemblies on the ends of each piece. This will also provide secure positions at opposite ends of the cable, for attaching two loads (e.g., two containers), such as for the dual-sided embodiments.
Yet another connection mechanism for connecting a container to the cable may be a quick acting rope grip, similar to those used to connect gondolas to wire ropes on ski lift systems.
At least one, and in some cases two pulleys or sheaves, may be used in the system. An advantage of using two sheaves is that when two baskets are used as in the dual-sided embodiments, there is clearance for the baskets to pass each other, without the need to move the winch to provide clearance. In the dual sheave embodiment, the sheaves should be able to rotate so that the pulley wheels may align themselves in the direction of the tension in the wire rope. If the architect or the building owners would like the two sheave installations to be less noticeable, deflector pulleys may be used.
The sheaves may be permanently or temporarily attached to the structure of the building in different ways. The choice may depend on the architect's attitude towards the appearance of the system on the building. For instance, the sheaves may be mounted on davits, making it possible to reach the roof level more easily especially if parapets need to be cleared. If desired, the davits could be folded out of sight, and the tension in the wire rope used to automatically erect them. In addition, openings in the parapets may be provided for rigging tiebacks.
The frame holding the sheaves may be hung over the side of the building, and may rest against the building face. The sheaves may also be mounted on outriggers that project from the roof, or from lower elevations. These outriggers may be rigidly affixed, or less obtrusively arranged to slide outward when tension is applied to the wire rope. A preferred installation for the purposes of the Fire Department may be to have one or two davits that are high enough to permit easy access to the roof level.
According to an embodiment of the invention, instructions may be provided to operate a system for reaching from outside an upper floor of a multi-story building, as described above with reference to one or more of
An embodiment of the invention is a system comprising a pulley attached to a building, a closed loop of cable installed around the pulley and being of sufficient length so as to reach, when deployed outside of the building, below the pulley to where emergency personnel gather in an area next to a base of the building when responding to a disaster situation in the building, and a winch around which the loop is to be operatively installed, the winch being located in the area next to the base. Another embodiment of the invention is a method comprising reaching from outside an upper floor of a multi-story building, by a) installing a closed loop of cable into a winch located in an area next to a base of the building, the loop being further connected around a pulley that is mounted on the roof or above the upper floor of the building, b) loading a container that is attached to the loop with equipment in the area next to the base of the building, and c) activating the winch in a first direction to raise the loaded container until it has reached approximately the upper floor while the winch remains in the area next to the base. Another embodiment is a method comprising reaching from outside an upper floor of a multi-story building, by a) installing a closed loop of cable onto a winch, the loop being further wrapped around a pulley that is mounted to a roof of the building or somewhere on the building above the upper floor, b) attaching equipment to the loop at an area next to a base of the building, and c) activating the winch to raise the attached equipment until it has reached the upper floor and then deactivating the winch to leave the equipment suspended at approximately the upper floor. Yet another embodiment is a method for reaching from outside an upper floor of a multi-story building, comprising a) installing a loop of cable onto a winch located in an area next to a base of the building, the loop being further wrapped around a pulley that is mounted to a roof of the building or somewhere on the building above the upper floor, b) attaching equipment to the loop in the area next to the base of the building, and c) activating the winch to raise the attached equipment until it has reached and is suspended approximately at the same level as the upper floor, wherein the winch remains fixed at a single location in the area next to the base until the attached equipment has reached the upper floor, and then d) decreasing tension in the loop as installed to position the suspended equipment closer to the building. Yet another embodiment is a method comprising installing a closed loop of cable into a winch located in an area next to a base of a structure, the loop being further connected around a pulley that is mounted on top or above an upper level of the structure, and activating the winch in a first direction to lower a load suspended by the loop. Yet another embodiment is a method comprising installing a loop of cable into a traction winch located in an area next to a base of a structure, the loop being further connected around a pulley that is mounted on top or above an upper level of the structure, and activating the winch in a first direction to raise a load suspended by the loop. A further embodiment of the invention is a system a system comprising a pulley attached to a structure, a loop of cable installed around the pulley and being of sufficient length so as to reach, when deployed outside of the structure, below the pulley to where personnel gather in an area next to a base of the structure when operating the system, wherein the loop of cable is removably secured to the area next to the base until it is to be arranged for use in one of raising and lowering a suspended load, between an upper level of the structure and the area next to the base. Yet another embodiment is a system comprising a pulley attached to a high-rise building, and a closed loop of wire rope installed around the pulley and being of sufficient length to reach, when arranged below the pulley, an area next to a base of the building.
To summarize, various embodiments of a method and system for accessing an upper floor of a multi-story building from the outside have been described. In the foregoing specification, the invention has been described with reference to specific exemplary embodiments thereof. It will, however, be evident that various modifications and changes may be made thereto without departing from the broader spirit and scope of the invention as set forth in the appended claims. For example, instead of or in addition to a container, a fire hose or electrical power cable may be attached to the container or the cable, so that the length of fire hose or cable is hoisted from a pumper or powered reel to the upper floor. Multiple loads may also be attached (e.g., multiple water pumps that may help deliver water to the upper levels of the structure, where such levels may be so high that the pressure needed to pump the water directly from the base would be too high for the hose). Also, although a single upper pulley is shown in the figures, more than one upper pulley may be installed in the system (either on the same face of the building, or on different faces at a corner of the building). This variation is particularly advantageous when the system has two containers, where the two pulleys then provide the clearance needed for the two containers to pass each other (while one is being raised and another is being lowered). In addition, the system may also be used in non-emergency situations, e.g. lifting or lowering heavy or bulky loads that do not fit into building elevators or may cause inconveniences for the tenants; and during construction modifications to avoid shifting long operations to nights or weekends. Also, some of the techniques described above in relation to buildings may be applied to certain other tall structures such as windmills and off-shore oil platforms. The specification and drawings are, accordingly, to be regarded in an illustrative rather than a restrictive sense.
This is a divisional application of co-pending application Ser. No. 12/434,521, filed May 1, 2009 (which will issue as U.S. Pat. No. 8,833,522 on Sep. 16, 2014), which is a continuation of application Ser. No. 11/185,518, filed Jul. 19, 2005 (which issued as U.S. Pat. No. 7,537,087 on May 26, 2009).
| Number | Date | Country | |
|---|---|---|---|
| Parent | 12434521 | May 2009 | US |
| Child | 14483801 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 11185518 | Jul 2005 | US |
| Child | 12434521 | US |
