Title:
Removable stairway
Kind Code:
A1


Abstract:
An adjustable stairway system provides access between a first elevation level and a second elevation level. The system includes a pair of expandable and retractable scissor stringers and multiple spaced apart treads joining the pair of stringers. The system further includes a first mounting assembly structured to allow a top portion of the stairway to be relatively permanently secured to a landing or other man-made structure, and second, different mounting assembly that allows a bottom portion of the stairway to be removably secured to natural terrain such as a beach. The system sometimes includes a control assembly to assist in expanding or retracting of the stairway.



Inventors:
Reeves, John T. (Fayetteville, GA, US)
Application Number:
11/710033
Publication Date:
08/30/2007
Filing Date:
02/23/2007
Primary Class:
International Classes:
E04F11/00
View Patent Images:
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Primary Examiner:
IHEZIE, JOSHUA K
Attorney, Agent or Firm:
STOUT, UXA & BUYAN, LLP (Laguna Hills, CA, US)
Claims:
What is claimed is:

1. An access system for providing access between a first elevation level and a second elevation level, the system comprising: a stairway device structured to be moved between a expanded configuration and a collapsed configuration, the stairway device including a stringer assembly having a proximal portion and a distal portion, and a plurality of treads connected to the stringer assembly; and an anchoring system for adjustably connecting the stairway device to and between a first elevation level and a second elevation level, the anchoring system including a first mounting assembly structured to be secured to a structure at the first elevation level and connectable to the proximal portion of the stringer assembly, and a second mounting assembly structured to be removably secured to a ground surface at a second elevation level and connectable to the distal portion of the stringer assembly.

2. The system of claim 1 wherein the second mounting assembly is structured to be insertable into natural terrain.

3. The system of claim 1 wherein the second mounting assembly comprises a support element includes a distal region structured to facilitate insertion and removal of the support element into natural terrain.

4. The system of claim 3 wherein said distal region is secured to an anchor selected from the group consisting of a buried tank, a buried bladder, a buried balloon, a pounding rod, and an auger.

5. The system of claim 3 wherein the support element distal region comprises a threaded distal region.

6. The system of claim 3 wherein the support element distal region comprises an auger.

7. The system of claim 1 wherein the second mounting assembly is slidably connectable to the distal portion of the stringer assembly.

8. The system of claim 7 wherein the second mounting assembly includes a support post having a threaded distal region structured to facilitate insertion and removal of the support element into natural terrain.

9. The system of claim 1 wherein the first mounting assembly is structured to be secured to an existing man-made structure.

10. The system of claim 9 wherein the second mounting assembly is structured to be insertable into natural terrain.

11. The system of claim 1 further comprising a control assembly effective to facilitate at least one of expanding and retracting of the stairway device.

12. The system of claim 11 wherein the control assembly comprises a gear assembly secured to a proximal portion of the stringer assembly.

13. The system of claim 12 wherein the gear assembly comprises a housing that forms a tread of the stairway device.

14. The system of claim 1 wherein said anchoring system further comprises one or more intermediate mounting assembly structured to be removably secured to a slope surface at an elevation level intermediate between said first and second elevation level and connectable to an intermediate portion of the stringer assembly.

15. The system of claim 14 wherein said anchoring system comprises at least two of said intermediate mounting assemblies.

16. The system of claim 14 wherein said intermediate mounting assembly comprises a support element that includes a distal region structured to facilitate insertion and removal of the support element into natural terrain.

17. The system of claim 16 wherein said distal region is secured to an anchor selected from the group consisting of a buried tank, a buried bladder, a buried balloon, a pounding rod, and an auger.

18. The system of claim 16 wherein the support element distal region comprises a threaded distal region.

19. The system of claim 18 wherein the support element distal region comprises an auger.

20. A retractable stairway system comprising: a stringer assembly having a proximal portion and a distal portion and including a pair of opposing scissor stringers and a plurality of treads joining together said stringers; and an anchoring system including a support element structured to be removably inserted into natural terrain; the stringer assembly being structured to be expandable and retractable between an extended configuration and a collapsed configuration respectively; wherein the proximal portion of the stringer assembly is directly secured to a man-made structure located at a first elevation level, and the distal portion of the stringer assembly is structured to be removably anchored to the second elevation level when the support post projects from natural terrain located at the second elevation level.

21. The system of claim 20 further comprising a control assembly effective to facilitate at least one of expanding and retracting of the stringer assembly.

22. A method of providing access between a structure and a ground level of variable elevation, the method comprising the steps of: securing to a structure located at a first elevation level a retractable and extendible stairway comprising a pair of movable scissor stringers comprising a plurality of pivotally connected links and a plurality of treads secured between the stringers, and a control system effective to assist in extending or retracting the stairway; extending the stairway, while a proximal portion of the stairway is secured to the structure, such that a distal portion of the stairway extends toward a second elevation level; removably anchoring the distal portion of the stairway at a second elevation level, and removably securing one or more intermediate mounting assembly between said proximal and distal end of the stairway by means of one or more removable support posts projecting from the ground.

Description:

This application claims priority pursuant to 35 USC §119(e) to U.S. Provisional Application Ser. No. 60/776,259, filed Feb. 24, 2006, which is hereby incorporated by reference herein in its entirety.

The present invention is drawn to methods and assemblies for providing adjustable access from one level to another, for example, from a platform such as a platform associated with a dwelling or other structure, which is located at a first elevation different to a second elevation to which access is desired to be gained.

Particularly, but not exclusively, in regions that are subject to accretion and/or erosion of sediment, sand, driftwood or other material, or which may be subject to periodic flooding or water inundation, providing or maintaining access to a given location may be difficult. For example, providing access to beach areas can be particularly troublesome since sand dunes, driftwood, and the like may accumulate or disappear within a given season. While access may sometimes be possible by walking through sand dunes or driftwood piles, returning to the higher elevation can be quite challenging; for example, climbing through sand can be physically exerting, and may not be practical for elderly or physically challenged persons.

In areas that are subject to strong storm surge and hurricanes there can be swift and dramatic shifting in shoreline, sand level, and water level that preclude the maintenance of a permanent stairway without frequent damage and destruction of the staircases. In particular, subsidence of the ground upon which at least part of the stairway is placed is a major problem leading to a need for improved means of gaining access to various outdoor features, such as beach surfaces.

U.S. Pat. No. 5,626,440 describes a retractable beach stairway adapted to be mounted on a plurality of piling on a dune. This stairway is slidably pivoted within a housing suitable for use as a walkway. When the stairway is to be employed, the housing pivots up at the distal end (that end closest to the beach) and a series of pulleys and cables located near the proximal end of the housing permits the stairway to be deployed by lowering from a cavity within the housing.

U.S. Pat. No. 6,526,706 describes a beach stairway comprising a stairway that may be placed on the sand and attached, via a series of cables, to a plurality of sand anchors located behind and lateral to the stairway. The sand anchors, and therefore the stairway, are removable.

U.S. Pat. No. 642,782 describes an iron staircase that can be adjusted to any angle of inclination. The stairway, particularly made for use in mines, stores, vineyards, and country houses has steps that are adjustable to whatever angle of inclination is given the frame.

U.S. Pat. No. 4,615,160 is an adjusting staircase having a pair of stringers to which are attached a pair of pantographs. The staircase is adjustable to various degrees of inclination. Each pantograph is enclosed in a casing having open ends.

There remains a need for an access system or access system joining different outdoor levels, for example, between a platform positioned on an upper level and a ground surface at a lower level, which is sufficiently robust to remain usable by people of all ages, which is also adjustable, retractable, and removable. Additionally, it would be advantageous to have a compact access system, capable of quick disassembly and removal during the off season, which is low maintenance, has a low impact on the environment (thus being compliant with relevant environmental and building codes) and which can be operated by a single person.

SUMMARY OF THE INVENTION

Accordingly, the present invention provides an easy to use, durable and adjustable and removable access system, specifically a stairway system, for providing pedestrian access, for example, between a bluff and a beach.

Generally, the access system of the present invention comprises a stairway device structured to be temporarily or permanently secured between an existing platform, landing or other man-made construction located at a first level, and natural terrain located at a second level. In an especially advantageous embodiment, the stairway device is structured to be relatively permanently (but removably) secured to the construction at the first level and temporarily secured to the natural terrain at the second level. For example, the construction at the first level may comprise a concrete or wooden walkway or platform connecting a house to an edge of a bluff above a shoreline. The natural terrain at the second level may comprise a sandstone surface or beach front located at an elevation below the first level.

In another, separate, embodiment the access system may comprise a manmade structure at a second level to which the man-made structure is semi-permanently (but removably) secured. However, in such an embodiment the stairway device preferably comprises two or more support posts which extend from the stairway device to the ground at the base level or slope and are temporarily, but securely, affixed to the base level of slope by means of an anchoring system, as discussed further below.

Preferably, the stairway device is structured to be movable between an expanded or extended configuration and a collapsed or retracted configuration. For example, the access system is designed such that it can be disposed in both an expanded or extended configuration for when the access system is in use as a stairway, and a collapsed or retracted configuration for when the system is not in use. Preferably, the system is designed to be movable between the extended configuration and the collapsed configuration by one or two adult human beings. In a preferred configuration, the stairway device is installed in a collapsed configuration, and then extended when desired by means of gravity, manual force, lock/break release, a cable, belt, threaded rod, or any other retraction (and/or extension) system that may be useful.

More particularly, when set up in the expanded or extended configuration, the stairway device defines a comfortable incline angle for users thereof, namely, those who use the access system to travel from the first level to the second level and vice versa. Preferably, the stairway device, when in use, has an inclination angle of about 60 degrees or less, or about 50 degrees or less, or about 45 degrees or less.

The stairway device is designed to have an adjustable length when in the expanded configuration. For example, the length may be selected based in part on the geology of the terrain, the slope of the terrain, and/or the distance between the first level and the second level.

In an exemplary embodiment, the stairway device comprises a stringer assembly having a proximal portion and a distal portion and comprising a pair of opposing scissor stringers and a plurality of treads joining together the pair of opposing stringers.

The length of the stairway device, when fully employed and extended, preferably does not exceed about 20 feet to about 25 feet measured between a top-most tread and a bottom-most tread. In certain cases, the stairway device may extend up to about 40 feet or up to about 45 feet or greater. Typically, the minimum length of the stairway device will not be less than about 5 feet, less than about 10 feet, or less than about 15 feet.

When discussing the dimensions of the stairs of the stairway device, the term “riser height” means the distance between the top surface of one tread and the top surface of the next tread above and/or below it. Generally, the riser height of the present invention will be in the range between about 4 inches and 12 inches; more preferably between about 6 inches and about 10 inches in riser height, optimally about 9 inches in riser height.

When discussing the dimensions of the treads of the stairway device, the term “width” means the distance along a single tread between a first and second stringer to which the treat is secured. The width of the treads on the present stairway will be between about 2 feet and about 8 feet in width, or optimally between about 4 feet and about 6 feet in width.

Particularly usefully, but not necessarily, the stairway device may in certain embodiments make use of one or more structural channels to support the stairs and/or to act as wheel guides for lifting equipment. These channels may be bolted, bracketed, welded, or otherwise attached to a structure or landing, with the “U”-shape facing upwards to permit the treads, stringers, and/or wheels to be stabilized and directed lengthwise along the channel rather than laterally. This may be of particular use when the stairway treads are about 6 feet or more in width.

When discussing the dimensions of the treads of the stairway device, the term “depth” means the distance between a front surface of the tread and a rear surface of the tread. The treads are at least about 8 inches in depth. Preferably the treads may be between about 8 inches and about 12 inches in depth. Preferably, the treads are about 9 inches in depth.

The stairway device is preferably designed to be easily, preferably manually, movable from the expanded or extended configuration to the collapsed or retracted configuration, for example, when access is no longer desired between the first level and the second level.

For example, an owner of the present access system may desire to use the system only on occasion, for example, seasonally, in order to gain access to and from a home located on an elevated bluff and a beach therebelow. The present invention allows the owner the ability to easily retract the stairway device, for example, during long-term non-use, or in order to hinder unauthorized persons from using the stairway device to gain access to his home from the beach. Alternatively, and preferably, the access system may be removed entirely from the points of securing the stairway device at the first and second levels and stored, for example, in a locked shed or garage to prevent theft.

The access system further comprises an anchoring system for securely anchoring the stairway device in place at the first level and the second level, and optionally at intermediate positions along the length of the stairway. The anchoring system is preferably designed to securely maintain the stairway device in the extended position, such that the stairway remains stable and fixed at the first level and the second level, and at intermediate positions as necessary for stability, during inclement or windy weather, for example, during a mild tropical storm surge, and/or high tidal conditions.

In a preferred aspect of the invention the anchoring system comprises a first mounting assembly structured to be connectable to the proximal portion of the stringer assembly and a second mounting assembly securable to a ground surface and structured to be removably connectable to the distal portion of the stringer assembly.

Preferably, the first mounting assembly comprises a bracket that is anchored to the landing or other construction at the first level. The proximal portion of the stringer assembly is structured to be attached to the bracket assembly thereby anchoring the stringer assembly to the first level.

In a preferred embodiment, the second mounting assembly comprises at least one, preferably two support posts removably connectable to the distal portion of the stringer assembly. Each support post preferably includes a distal end structured to be inserted a sufficient depth into the ground, and a proximal end removably connectable to the distal portion of the stringer assembly. For example, a distal end of the support post may comprise an auger or other threaded structure permitting the support post to be removably secured into the ground. The distal end of the support post may be modifiable in size, shape and/or pitch depending on the type of ground or earth the post is to be inserted. The proximal portion of the support post may be slidably inserted into a receiving collar located on the distal region of the stringer assembly to provide removable connection therebetween. However, other anchoring methods for receiving the support posts can easily be envisioned by the person of ordinary skill in the art. Such methods may include the use of buried, weighted tanks or balloons, such as a balloon made from Geotex tubing, filled with water, sand, or other material than may remain or be removed following removal or reorientation of the stairway system. Such tanks may be comprised of, for example, metal, plastic or wood.

Other possible such anchoring means may include a removable pounding rod tip for receiving the lower end of a support post. The pounding rod is first inserted into the base level, for example, sand, clay and the like. The pounding rod may be partially or wholly hollow and contain two or more slits or holes through which two or more corresponding flexible slats may be extended when the pounding rod is placed into the base level. An actuating system, for example, a threaded rod insert affixed to a slidable collar to which said two or more flexible slats are attached in a manner such that actuation of the threaded rod will lower the collar, thereby extending the two or more slats through the corresponding slits or holes, thereby securely anchoring the support post at the base level. Removal of the pounding rod is accomplished by employing the actuating system in reverse, thereby retracting the slats into the pounding rod through the slits or holes.

Intermediate mounting assemblies will generally be of the same type(s) as described above for the second mounting assembly, i.e., will comprise a removable anchoring system. In embodiments wherein the second mounting assembly is affixed to a semi-permanent ground level platform, the present invention will comprise intermediate mounting assemblies comprising a removable anchoring system. The intermediate mounting assemblies may be placed at intervals along each side of the stairway, for example, approximately every 6 feet, or approximately every 5 feet, or approximately every 4 feet or approximately every 3 feet along the length of the stairway between the proximal and distal ends of the stairway in its extended configuration.

The present access system of the present invention may be constructed from wood, plastics, composite materials, stainless steel, and/or other metals or metal alloys. However, it is preferred that the stringer assembly and anchor assembly are both made in whole or in part of strong, light, weather resistant materials, for example, marine-grade aluminum. This will help maintain the stairway functioning and relatively unaffected by rain, snow, water, salt and sun for long periods of time.

In a preferred embodiment, the access system of the present invention further comprises a retraction system for facilitating changing of the stairway device between the extended configuration and the retracted configuration. More specifically, in one embodiment, the retraction system is designed to facilitate drawing of the distal portion of the stringer assembly toward the proximal portion when it is desired to remove or store the stairway device for periods of non-use. The retraction system may comprise, for example, one or more cables, belts, threaded rods, or worm gears affixed to the distal portion of the stairway device, and a gear assembly, including various gears, pulleys and/or levers, located at the proximal portion of the stairway device and effective to draw the distal portion of the stairway device by means of the cable. The cable may be stainless steel, and the gears pulleys and/or levers may be constructed of a corrosion resistant material such as a corrosion resistant metal, for example, stainless steel, bronze or aluminum.

Each scissor stringer, when in the extended state, comprises a plurality of approximately vertical links and a plurality of approximately horizontal links, wherein each approximately vertical link is pivotally attached to at least one approximately horizontal link. The pivotal attachment may comprise a peg, bolt, rivet or post joining at least two links through a hole on at least one of the links. The peg or post may be welded or otherwise connected to or formed from one or more of the attached links. Preferably, the pivotal attachment is a riveted connection.

The depth of the treads is variable, but will generally be shorter than the length of the approximately horizontal link to which it is joined, and is preferably no less than about half this length.

In a preferred embodiment of the invention, each approximately vertical link is pivotally attached to three approximately horizontal links and each approximately horizontal link is pivotally attached to three approximately vertical links so as to form a scissor-like structure that can be retracted, for example, by connecting a cable, belt, threaded rod, or worm gear from a proximal end to a distal link, and pulling, winding, spinning, or reeling the cable, belt, threaded rod, or worm gear so that the scissor stringer closes, thereby bringing the distal end of the stairway closer to the proximal end. The ends of the stairway will generally comprise links with fewer connections than this. The cable, belt, threaded rod, or worm gear may be pulled, spun or reeled mechanically, such as by using an electrically activated capstan or windlass, or manually, such as by using a lever or other actuating device.

In another embodiment of the invention, each approximately vertical link (except near the distal and proximal ends) is pivotally attached to four or more approximately horizontal links and each approximately horizontal link is pivotally attached to four or more approximately vertical links. Although heavier than the simpler scissor stringer described above, an advantage to such a configuration is that when extended the sides of the stairway may be higher and thus provide a person some lateral support when ascending or descending the staircase. In either case, the tops of the approximately vertical links may be connected with cable, rope or line such that it provides a handhold when the stairway is in the extended position. In one embodiment, a cable, rope, rod, wooden member or line forming a handhold is part of the stairway retraction system.

In a preferred mode, one or more approximately vertical links at or near the proximal, distal, and/or intermediate portions of the scissor stringer is attached to a metal sleeve. The link and sleeve may be joined using a fastener such as a screw or rivet, or maybe welded together. The sleeve is joined to the link or links in a manner such that it is approximately vertical when the stairway is in the fully extended position. In another embodiment, although not necessarily present in every embodiment of the invention, the sleeve is adjustable, in such a manner that its orientation with regard to the angle of inclination of the stairway may be finely tuned in the event that the stairway is moved.

Any combination of two or more features described herein is included within the scope of the present invention provided that the features in each such combination are not mutually inconsistent.

These and other aspects and advantages of the present invention are apparent in the following detailed description and claims, particularly when considered in conjunction with the accompanying drawings in which like parts bear like reference numerals.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a depiction of a side view of a retractable access system in accordance with an embodiment of the invention, showing a first mounting assembly for coupling a stringer assembly to an existing platform at a first elevation level, and a second mounting assembly located at a distal portion of the stairway for coupling the stringer assembly to a sandy beach surface at a second elevation level.

FIG. 2 is a depiction of a front view of the stringer assembly and treads connected therebetween, and the second mounting assembly including support posts inserted into the sandy beach.

FIG. 3 is a perspective view of the first mounting assembly of the present invention.

FIG. 4 is a side view of the second mounting assembly including a support post having an auger foundation.

FIG. 5 is a diagrammatical view of a control system useful in the extension or retraction of the stairway system of the present invention.

FIG. 6 is a side view of a support post removably affixed to a tank, bladder to balloon foundation.

FIG. 7 is a front view of a support post removably affixed to a tank, bladder to balloon foundation.

FIG. 8 is a view of a support post removably affixed to a pounding rod foundation.

DETAILED DESCRIPTION

Turning now to FIG. 1, an access system or stairway system in accordance with the invention is shown generally at 10. The access system 10 is structured to provide safe, convenient access between a first elevation level 12 and a second elevation 14, for example, between an existing platform, landing or other man-made construction located on an elevated bluff 16, and a natural terrain, such as a sandy beach 17, clay, sandstone or other relatively soft terrain located below the bluff 16.

Preferably, the access system 10 comprises a adjustable stairway device 20 that is removably anchored between the first elevation level 12 and the second elevation level 14. Advantageously, the stairway device 20 is designed to be moved between an extended position such as shown in FIG. 1, and a retracted position (not shown). The access system 10 further comprises an anchoring system for securely anchoring the stairway device 20 in place in the extended position, even during inclement or windy weather, for example, during a mild tropical storm surge, and/or high tidal conditions.

More specifically, in the shown embodiment, the stairway device 20 comprises a movable stringer assembly 22 having a proximal portion 22a and a distal portion 22b. Advantageously, the stringer assembly 22 is structured to be movable between an expanded or extended configuration (such as shown in FIG. 1) and a collapsed or retracted configuration, for example, a fully retracted configuration (not shown). Preferably, the assembly is designed to be movable between the expanded or extended configuration and the collapsed or retracted configuration by one or two adult human beings.

Turning now as well to FIG. 2, the stringer assembly 22 generally comprises a pair of opposing scissor stringers 24 made up of pivotally connected links 25 and having a plurality of treads 26 interconnected therebetween. When the stairway 10 is in the expanded or extended configuration, the treads 26 are spaced apart from one another at substantially regular, convenient intervals for stepping.

The treads may be between about 8 inches and about 12 inches in depth. The treads may be between about 2 feet and 8 feet in width. Preferably, the treads are at least about 9 inches in depth and at least about 4 feet to 6 feet in width.

Turning back to FIG. 1, the anchoring system generally comprises a first mounting assembly 28 and a second mounting assembly 30 for connecting the stairway device 20, to both the first elevation level 12 and the second elevation level 14 respectively.

In the shown embodiment, the first mounting assembly 28 is differently structured from the second mounting assembly 30. More specifically, the first mounting assembly 30 is structured to be securable to a platform or other existing structure 34 at the first level 12 and is useful for coupling the proximal portion 22a of the stringer assembly 22 to the existing structure 34. The second mounting assembly 30 is designed to be secured to the natural terrain 17 located at the second level 14 and is useful for coupling the distal portion 22b of the stringer assembly 22 to the natural terrain 17. For example, the second mounting assembly 30 comprises a support post 42 such as shown in FIGS. 1, 2 and 4.

More specifically, turning now to FIG. 3, the first mounting assembly 28 may comprise one or more mounting brackets 36 that are secured to the platform or other existing structure 34. The mounting brackets 36 are securely, preferably permanently, fastened to the existing structure 34, for example, by means of bolts (not shown) inserted through apertures 36a. Turning now as well to FIG. 1, each mounting bracket 36 includes structure, for example, an elongated projection 36b having a T-shaped cross-section, which is connectable to, for example, received into, corresponding structure, for example slots 36c, located on the stairway device 66.

Referring now to FIGS. 1, 2 and 4, the second mounting assembly 30 may be structured to be removably fixable into a ground surface. For example, the second mounting assembly 30 may comprise a support element or support post 42 having a distal region structured to be inserted, for example driven, into the ground. For example, the distal region may comprise an auger foundation 44 or other structure effective to facilitate driving and/or anchoring of the support post 42 into the ground, for example, into a primarily sand-based terrain, such that the support post 42 is inserted a sufficient depth to stabilize the stairway 10 when in use.

Preferably, the support post 42 is structured to accommodate the load condition of the stairway device 20, the type of terrain in which the support post 42 will be inserted, and/or other factors. For example, the length of the support post 42, the size and/or pitch of the auger foundation 44, and/or the material of which the support post 42 is made, may be selected to accommodate a load condition of the access system 10.

The support post 42 is connectable to the stringer assembly distal portion 22b in any suitable manner. Preferably, the support post 42 is designed to facilitate secure but removable coupling between the stringer assembly 22 and the second elevation level 14, for example, by means of a collar 46 for slidably receiving a railing post 48 of the stairway device 20, such as shown in FIGS. 2 and 4. Collar 46 may include aperture 47 for receiving a peg 47a of support post 48 in order to enable height adjustable connection between a bottom-most tread 26 of the stairway 10 and the ground surface. The peg may, in a preferred embodiment, comprise a safety bolt which is removed by means of a key or other tool, thus preventing unintentional removal of the bolt. The safety bolt may be made flush with the collar as an additional safety measure.

As shown in FIG. 1, when the system 10 is set up in the expanded or extended configuration, the stairway device 20 defines a comfortable incline angle for users thereof, namely, those who use the system 10 to travel from the first level 12 to the second level 14 and vice versa. Preferably, the stairway device 20, when in use, has an inclination angle of about 60 degrees or less, or about 50 degrees or less, or about 45 degrees or less.

Referring now to FIGS. 1, 3 and 5, the system 10 further comprises a control assembly 60 fixed to the stringer assembly 22 and functional to cause or facilitate retraction and/or expansion of the stringer assembly 22.

For example, the control assembly 60 may comprise a gear assembly 64 mounted to the stringer assembly proximal portion 22a and a connector cable 65 functionally connecting the gear assembly 64 to the stringer assembly distal portion 22b. The gear assembly 64 includes a housing 66 which encloses gear components such as shown in FIG. 5. The housing 66 may include a top surface 66a which functions as a tread, for example, a top-most tread, such as shown in FIGS. 1 and 3. The housing 66 may include structure, for example, the mounting slots 36c described elsewhere herein, for coupling the stairway device 20 to the first mounting assembly 28.

The control assembly 60 is preferably designed to be effective in drawing, or at least assist in drawing, the distal portion 22b of the stringer assembly 22 toward the proximal portion 22a of the stringer assembly 22 when it is desirable to place the stairway device 20 in the retracted configuration in which the stringers 24 are folded in a compact manner. Likewise, the control assembly 60 may be additionally designed to be effective in expanding, or at least assist in expanding, the stringer assembly 22 from the retracted configuration to the extended or expanded configuration.

Referring specifically to FIG. 5, the gear assembly 64 may include an arrangement of gears 82 and a governor 84 for effecting controllable rotation of a transfer shaft 88. Rotation of the shaft 88 may be accomplished manually or through the use of a motor, in order to effect tightening and loosening of the cable 65, which winds around a spool 89 on the shaft 88. The tightening, or drawing, and loosening of the cable causes, or at least assists to cause, the retraction and controlled expansion of the stringer assembly 22. A brake 92 and removable break handle 94 may also be provided as shown. The gear arrangement shown provided for the purposes of example only and the present invention is not intended to be limited thereto. It is to be appreciated that other suitable control systems for accomplishing the purposes and objectives of the present invention, for example, controlled expansion and contraction of the stairway device 20, can be provided within the scope of the present invention.

The system 10 may be structured such that utilization of the control assembly 60 for expanding or retracting the stairway device 20 is performed while the stringer assembly 22 is secured to the first mounting assembly 28 and is disconnected from the second mounting assembly 30. Thus, in this embodiment, when the stairway device 20 is fully retracted, it will be positioned in a compact, folded configuration directly adjacent the structure 34 at the first elevation level 12.

The present invention also provides methods of providing access between a structure and a ground level of variable elevation. For example, a method in accordance with the invention generally comprises the steps of permanently securing a proximal portion of a retractable stairway to a structure located at a first elevation level and anchoring a distal portion of the stairway to natural terrain located at a second elevation level by means of one or more support posts removably projecting from the ground.

The present system 10 is preferably designed to remain fixed in place even during a moderate storm surge. This can be accomplished in a number of ways. For example, the components of the system 10 may be made of strong but light weight materials, such as marine grade aluminum. In addition, the system 10 is preferably designed to adjust the length of the stairway as necessary, for example, from season to season. As the natural terrain and bluff structure changes, for example due to erosion, tidal action and the effects of weather, the present system 10 can be removed and adjusted to suit these changing conditions. For example, it can be appreciated that the system 10 shown is structured such that during the off-season, for example, when beach access is not desirable, the stairway can be stored in a retracted, locked position against the end of or on top of the landing at the top of the bluff, or the support post and anchoring system can be removed entirely and the system stored off-site. The support posts can be removed from the ground and stored for later use. When the landscape changes, for example, when the distance between the landing and the beach changes, for example, from season to season, or year to year, the effective length of the stairway (from top-most tread to bottom-most tread) can be changed as appropriate, simply by moving the support post and/or anchoring system to the appropriate location and extending the stairway a required amount and/or adding or removing portions to the stringers.

Referring now to FIG. 6, an alternative foundation and anchoring system is shown in side view, whereby the bottom portion of a support post 42 is slidably received by a sleeve 54 which may comprise an aperature 56 into which a peg 56a is insertable to reversibly lock the support post to the foundation 70. In this embodiment of the invention, the foundation 70 comprises a tank, bladder or balloon which is partly or completely buried in the sand or clay and which may be partly or completely filled with water, sand, other ballast, or a mixture of these. Preferably, the foundation 70 comprises a closable port 72 for filling or draining, and may be constructed to metal, plastic, synthetic fiber, fiberglass, and the like.

Referring now to FIG. 7, the same foundation 50 is shown in front view, and demonstrating that a single foundation 70 may be elongated to comprise two sleeves 54 for receiving support posts 42 from second 30 or intermediate mounting assemblies originating in each stringer.

Referring to FIG. 8, another embodiment of the foundation is shown comprising a pounding rod assembly removably affixed to a sleeve 58 comprising an aperature 59 for receiving the end of support post 42 and a peg or pin 59a for holding the support post in place. The main body 53 of the pounding rod 72 is substantially hollow and contains an actuating system for extending anchoring slats 55 when the pounding rod has been inserted into the ground, or for retracting such slats within the body 53 of the pounding rod.

Any and all features described herein and combinations of such features are included within the scope of the present invention provided that the features of any such combination are not mutually inconsistent.

While this invention has been described with respect to various specific examples and embodiments, it is to be understood that the invention is not limited thereto and that it can be variously practiced within the scope of the following claims.