WO2013091097A1

WO2013091097A1 - Lifting staircase assembly

Info

Publication number: WO2013091097A1
Application number: PCT/CA2012/050912
Authority: WO
Inventors: Jaimie F. BORISOFF; A. Gordon HANDFORD; Danny Leland; Ernst C. JANZEN
Original assignee: British Columbia Institute Of Technology
Priority date: 2011-12-23
Filing date: 2012-12-19
Publication date: 2013-06-27

Abstract

A lifting staircase assembly is operable between a first level and a second higher level. The assembly includes a staircase frame which extends longitudinally between a first platform at a first end and a second platform at a second end. The staircase frame is pivotally supported at a central location for movement between a first position in which the first platform is at the first level and the second platform is at the second level and a second position in which the first platform has been raised to the first level and the second platform has been lowered to the first level. The staircase frame defines a functional stairway between the first and second levels in both positions. In some embodiments, the first and second platforms may counterbalance one another for ease of operation between the first and second positions.

Description

LIFTING STAIRCASE ASSSE BLY

This application claims priority to U.S. provisional application Serial No. 61/580,043, filed December 23, 2011.

FIELD OF THE INVENTION

The present invention relates to the field of load transportation from one level to another and in particular to the ascending and descending of persons of compromised mobility by a means in lieu of stairs.

BACKGROUND

Staircases employed in and outside of buildings and other structures pose significant difficulties for individuals of compromised mobility such as those in wheelchairs, scooters/personal vehicles and for parents with children in strollers and other perambulators. The solutions are varied and are plagued with difficulties and range from elevator lifts, to moving chair arrangements to ramps.

In stair structures extending a vertical distance that is less than a building story, such as those typically used near the entrance to a building, a separate elevator lift is not always practical, particularly in outdoor environments. In such cases, separate ramps or moving chair arrangements may be provided which facilitate vertical travel by a personal vehicle.

One drawback to the use of a separate ramp to provide personal vehicle access to elevated surfaces is that suitable ramps consume relatively large amounts of space. As a result, existing buildings must often be substantially altered to accommodate the installation of a ramp. In many circumstances, space constraints surrounding the building make installation of a ramp impossible. Furthermore, permanent ramps significantly change the exterior appearance of a building, and may be seen as unsightly. Temporary ramps are impractical and do nothing to increase the independence of the user. It would be required that another person put the ramp in place for use.

Moving chair arrangements offer a solution in such low rise environments. Moving chair arrangements comprise a chair that slides diagonally up and down the stairway. Such arrangements require that the personal vehicle be separately transported up or down the stairway. Because personal vehicles can be quite heavy, separate transport of the personal vehicle can be difficult. Moreover, the movable chair itself, when not in use, nevertheless occupies stairway space and dictates the appearance of the staircase. Moreover, this has often been considered an indoor solution as, for use outdoors, exposure of the moving chair to the elements would be detrimental (although they are occasionally found in use outdoors). It also possible for a movable chair mechanism to be fitted with a platform for use by a person in a wheelchair or otherwise (these are sometimes called an inclined platform lift).

Separate vertical platform lifts have also been employed for such low rise environments for use in situations in which there is inadequate room for an access ramp, or the height renders a ramp simply impractical. Such devices, however, while consuming less space than a ramp, nevertheless consume valuable access space and dictate certain architectural parameters.

Moreover, separate wheelchair lifts may be impossible to implement in hallways or other narrow environments. Another drawback of vertical platform lifts is their difficulty of entry and exit, particularly by a person in a wheelchair. For instance, the use of these lifts often requires a wheelchair user to open a door to exit while facing backwards due to inadequate turning space within the confines of the lift.

In an attempt to address some of the concerns of the separate vertical lift, lifts have been developed that cooperate with a staircase to provide a lift that fits within a hallway or narrow environment. One such unit provides a lift that is disposed directly in front of a low rise staircase that extends from a lower surface to an upper surface. The lift provides vertical transport of wheelchairs from the lower surface to the level of the upper surface. When the lift rises, the stairs collapse upward to form a bridge platform that allows travel from the lift platform over the area normally occupied by the staircase to the destination upper surface.

A drawback of such designs is that they require space equivalent to the area of the lift platform either completely in front of or completely behind the staircase. In some cases, such area is not available. Moreover, because the lift platform is located completely outside the footprint of the staircase, the lift platform creates a potentially displeasing architectural discontinuity with the surface at which it normally rests while not in operation. Such discontinuities significantly affect the appearance of an architectural structure.

A feature common to all the above lifts is typically slow operational speeds {e.g. 0.04-0.15 m/s). It would be desirable to provide a mechanism that reduces the speed taken to travel up or down to an elevated surface, in order to reduce one of the common barriers to full community participation and quality of life for the elderly or people with disabilities. It is also known that reliability is a desirable feature of lift mechanisms: that is providing full operational capabilities in times of power failures.

US Patent No. 5,937,971 by Storm discloses an example of a staircase that converts to a lift mechanism. A complex tread positioning mechanism is required to align the stair treads with one another to form a common horizontal load supporting platform. Considerable power is then required to displace the platform including the tread positioning mechanism between a first level and a second level.

It is fair to say that while there have been well intentioned efforts in the field of combining lifts and stairs, there are limiting drawbacks to each and every known system to date.

It is an object of the present invention to obviate or mitigate the above disadvantages.

SUMMARY OF THE INVENTION

According to one aspect of the invention there is provided a lifting staircase assembly for operation between a first level and a second level which is greater in elevation than the first level, the assembly comprising:

a staircase frame extending in a longitudinal direction between a first end and a second end;

a support frame supporting the staircase frame thereon for movement between a first position in which the staircase frame ascends from the first end at the first level to the second end and a second position in which the staircase frame ascends from the second end to the first end at the second level; and a load bearing platform supported on the first end of the staircase frame for movement therewith between the first position in which the load bearing platform is supported at the first level and the second position in which the load bearing platform is supported at the second level;

wherein the staircase frame defines a longitudinally extending functional stairway between the first and second ends of the staircase frame for providing access between the first and second levels in at least one of the first and second positions of the staircase frame.

Much research has been done around stair climbing and falls in the elderly. The needs of wheelchair users for home access are obvious, and they are often limited in most neighbourhoods with single family houses. It is known that exercise such as stair climbing can improve balance in the elderly, therefore reducing the chances of a fall. It is also desirable in certain circumstances for an elderly person to have a choice to not use the stairs (e.g., when they are carrying something, or it is slippery). Overall, it is desirable to have choices in home access which are truly inclusive, (offering a choice of stairs or an efficient lift whenever it is wanted) while at the same time keeping the aesthetics of the structure or house intact. Prior to the present invention, no such solution has apparently been available.

The present invention provides a structure (such as home) access solution which may reduce the stigma of requiring assistance to access a second level of a structure and reduces device abandonment (which may lead to unsafe stair use). The staircase lift of the present invention may further promote the dignity and safety of the user, and may encourage the acceptance of accessibility technology. Furthermore, the present invention provides an inclusive solution that allows for quick and easy entry and egress into a structure to provide an opportunity for increasing a person's participation in society.

These and other advantages of the present invention will become more apparent to those skilled in the art upon reviewing the description of the preferred embodiments of the invention, in conjunction with the figures and examples. Preferably in at least one of the first and second positions of the staircase frame the second end of the staircase frame is aligned with a respective one of the first and second levels different from the first end of the staircase frame so as to define the longitudinally extending functional stairway between the first and second levels.

Preferably both i) the second end of the staircase frame is at the second level in the first position and ii) the second end of the staircase frame is at the first level in the second position such that the staircase frame defines a longitudinally extending functional stairway between the first and second ends of the staircase frame at respective ones of the levels in both the first and second positions of the staircase frame.

Preferably the staircase frame is securable in fixed relation to the support frame in both of the first and second positions.

Preferably the staircase frame is supported for pivotal movement relative to the support frame about a horizontal pivot axis oriented perpendicularly to the longitudinal direction of the staircase frame and located at an intermediate location between the first and second ends of the staircase frame.

The horizontal pivot axis is preferably longitudinally centered between the first and second ends of the staircase frame.

When the staircase frame is supported on the support frame at an intermediate location between opposing ends of the staircase frame, preferably a counterbalance member is supported on the staircase frame adjacent the second end of the staircase frame so as to be arranged to counterbalance the load bearing platform in relation to the intermediate location.

Preferably a linkage couples the load bearing platform to the staircase frame such that the platform remains horizontal throughout movement between the first and second positions of the staircase frame. More particularly, the linkage may comprise a link which is parallel to the longitudinal direction of the staircase frame.

The assembly may also include a second platform supported on the second end of the staircase frame so as to be arranged to support a load thereon for movement with the staircase frame between the first position in which the auxiliary platform is at the second level and the second position in which the auxiliary platform is at the first level.

When there is provided a horizontal landing supported at the second level preferably the load bearing platform is aligned with the landing in the second position and the auxiliary platforms is aligned with the landing in the first position.

The lifting staircase assembly preferably further comprises a railing assembly which includes i) a railing member pivotally coupled to the support frame at a location spaced above the staircase frame, and ii) at least one upright pivotally coupled between the railing member and the staircase frame. In this instance pivotal coupling of the staircase frame to the support frame results in the railing member and the staircase frame defining a pair of parallel links of a four-bar parallel linkage.

Preferably the railing assembly includes a first upright adjacent the first end of staircase frame to which the load bearing platform is coupled in fixed relation such that the load bearing platform remains horizontal throughout movement of the staircase frame between the first and second positions.

When the staircase frame includes a plurality of tread members at spaced apart positions in the longitudinal direction so as to define the stairway between the first and second ends of the staircase frame, preferably the tread members define a tread surface which is horizontal in both the first and second positions, and may remain horizontal throughout movement of the staircase frame between the first and second positions.

More particularly, the tread members are preferably pivotally coupled to the staircase frame for pivotal movement about respective horizontal axes oriented perpendicularly to the longitudinal direction of the staircase frame and a link member preferably extends in the longitudinal direction of the staircase frame in pivotal connection with each tread member at a location spaced equidistant from the respective axes of the tread members. Pivotal coupling of both the link member and the staircase frame results in the link member and the staircase frame defining a pair of parallel links of a four-bar parallel linkage. In a preferred embodiment the link member is pivotaliy coupled to the support frame below a pivotal coupling between the staircase frame and the support frame so that the link member spans in the longitudinal direction of the staircase frame below the tread surfaces of the tread members.

When there is provided a horizontal landing supported at the second level which includes a forward edge against which the load bearing platform is aligned and abutted with in the second position, preferably the longitudinal direction of the staircase is parallel to the forward edge.

In some embodiments a biasing member is coupled between the staircase frame and the support frame so as to be arranged to bias the staircase frame from the first position towards the second position.

The assembly may further comprise an actuator coupled between the staircase frame and the support frame so as to be arranged to drive movement of the staircase frame between the first and second position.

The lifting staircase assembly is particularly well suited for use in combination with a mobility assistance device selected from the group consisting of a wheelchair, a scooter, stroller, perambulator and personal vehicle.

According to a second aspect of the present invention there is provided a method of conveying a load between a first level and a second level in greater elevation that the first level, the method comprising:

a) providing a lifting staircase assembly comprising:

i) a staircase frame extending in a longitudinal direction between a first end and a second end;

ii) a support frame supporting the staircase frame thereon for movement relative to the support frame between opposing first and second positions in which the staircase frame defines a longitudinally extending functional stairway between the first and second ends of the staircase frame for providing access between the first and second levels in at least one of the first and second positions of the staircase frame; and

iii) a load bearing platform supported on the first end of the staircase frame for movement therewith relative to the support frame;

b) positioning the staircase frame in the first position in which the staircase frame ascends from the first end at the first level to the second end and the load bearing platform is supported at the first level;

c) placing a load on the load bearing platform; and

d) displacing the staircase frame and the load bearing platform relative to the support frame from the first position to the second position in which the staircase frame ascends from the second end to the first end at the second level and the load bearing platform is supported at the second level.

Preferably the staircase frame is fixed relative to the support frame at the second position prior to removing the load from the load bearing platform at the second level.

When the staircase frame is supported for pivotal movement relative to the support frame about a main pivot axis between the first and second positions, the method preferably includes either: i) supporting a counterbalancing mass on the second end of the staircase frame which substantially counterbalances the load on the load bearing platform about the main pivot axis; ii) providing a biasing force acting on the staircase frame to urge the staircase frame from the first position towards the second position so as to substantially counterbalance the load on the load bearing platform about the main pivot axis; or iii) any combination thereof.

Various embodiments of the invention will now be described in conjunction with the accompanying drawings in which:

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 is a perspective view of the lifting staircase assembly according to a first embodiment of the present invention;

Figure 2 is another perspective view of the assembly according to the first embodiment of Figure 1 showing the tread linkage below the tread members;

Figure 3 is a top plan view of the assembly according to the first embodiment of Figure 1 ; Figure 4 is a sectional view along the line 4-4 in Figure 3 showing the assembly according to the embodiment of Figure 1 in the first position of the staircase frame;

Figure 5 is a sectional view along the line 4-4 in Figure 3 showing the assembly according to the embodiment of Figure 1 in the second position of the staircase frame;

Figure 6 is a perspective view of a second embodiment of the lifting staircase assembly;

Figure 7 is a sectional view along the line 4-4 in Figure 3 showing an assembly according to a third embodiment of the lifting staircase assembly;

Figure 8 is a perspective view of a fourth embodiment of the lifting staircase assembly shown in the first position of the staircase frame; and

Figure 9 is a perspective view of the assembly according to the fourth embodiment of Figure 8 shown in the second position of the staircase frame.

In the drawings like characters of reference indicate corresponding parts in the different figures.

DETAILED DESCRIPTION

A detailed description of one or more embodiments of the invention is provided below along with accompanying figures that illustrate the principles of the invention. As such this detailed description illustrates the invention by way of example and not by way of limitation. The description will clearly enable one skilled in the art to make and use the invention, and describes several embodiments, adaptations, variations and alternatives and uses of the invention, including what we presently believe is the best mode for carrying out the invention. It is to be clearly understood that routine variations and adaptations can be made to the invention as described, and such variations and adaptations squarely fall within the spirit and scope of the invention.

In other words, the invention is described in connection with such embodiments, but the invention is not limited to any embodiment. The scope of the invention is limited only by the claims and the invention encompasses numerous alternatives, modifications and equivalents.

Numerous specific details are set forth in the following description in order to provide a thorough understanding of the invention. These details are provided for the purpose of example and the invention may be practiced according to the claims without some or all of these specific details. For the purpose of clarity, technical material that is known in the technical fields related to the invention has not been described in detail so that the invention is not unnecessarily obscured. Similar reference characters denote similar elements throughout various views depicted in the figures.

This description of preferred embodiments is to be read in connection with the accompanying drawings, which are part of the entire written description of this invention. In the description, corresponding reference numbers are used throughout to identify the same or functionally similar elements. If and when used herein relative terms such as "horizontal", "vertical", "up", "down", "top", "bottom", "distal", and "proximal", as well as derivatives thereof (e.g. "horizontally", "downwardly", "upwardly", etc.) should be construed to refer to the orientation as then described or as shown in the drawing figure under discussion. These relative terms are for convenience of description and are not intended to require a particular orientation unless specifically stated as such. Terms including "inwardly" versus "outwardly," "longitudinal" versus "lateral", "adjacent" and the like are to be interpreted relative to one another or relative to an axis of elongation, or an axis or center of rotation, as appropriate. Terms concerning attachments, coupling and the like, such as "connected" and "interconnected," refer to a relationship wherein structures are secured or attached to one another either directly or indirectly through intervening structures, as well as both movable or rigid attachments or relationships, unless expressly described otherwise.

In the present disclosure and claims, the word "comprising" and its derivatives including "comprises" and "comprise" include each of the stated integers but does not exclude the inclusion of one or more further integers or elements. The terms cords and cording may be used interchangeably.

As used herein, a "stair riser" or "riser" refers to the near-vertical element in a set of stairs, forming the space between a step and the next. It may be (but is not necessarily) slightly inclined from the vertical so that its top is closer than its base to the person climbing the stairs.

As used herein the horizontal part on which one steps is called the

"tread".

As used herein, the term "baluster" (also known as a spindle or stair stick) is a moulded shaft, square or lathe-turned form, made preferably (but not exclusively) of stone or wood or metal or plastic, standing on a unifying footing, and supporting the coping of a parapet or the safety handrail (also known as the banister) of a staircase. Multiplied in this way, they collectively form a "balustrade".

The present invention provides a highly functional combination of staircase and lift, which has the appearance and function of a "normal" set of stairs when in place in sideways configuration and adjacent to a building. As such, the critical issue of aesthetics and neighbourhood conformity has been addressed. One key feature of the staircase lift is its operation across a pivot point to raise and lower substantially horizontal landing platforms at the extremity of each end of the stairs. What this means is that loads, whether human, animal or cargo are placed on a platform, secured and then raised or lowered to the desired new height, all without moving the loads from the original "loading" platform. In addition, all of this is achieved without in any way compromising the form and functionality of the stairs at either the final pivot positions.

Referring to the accompanying figures there is illustrated a lifting staircase assembly generally indicated by reference numeral 10. The assembly 10 provides both the function of a staircase and the function of a lift for a mobility assistance device between a first level 12 and a second level 14 which is greater in elevation than the first level. The mobility assistance device may comprise a wheelchair, a scooter, a stroller, a perambulator, or a personal vehicle for example. The staircase assembly 10 is particularly suited for use with a building, for example a house having a surrounding approach at ground level defining the first level 12 and a with horizontal landing spaced above the ground defining the second level 14. Typically, a doorway or other entry into the building communicates with the landing at the second level. The landing may further comprise a common forward edge 16 relative to which the lifting staircase assembly is operable. The forward edge spans the full length of the assembly parallel to the front wall of the building in the illustrated embodiment.

Although plural embodiments of the lifting staircase assembly 10 are described and illustrated herein, the common features of the first three embodiments of Figures 1 through 7 will first be addressed.

In each instance, the assembly 10 generally includes a staircase frame 18 which is elongate in a longitudinal direction between a first end 20 and a second end 22. The staircase is supported on a suitable support frame 24 such that the longitudinal direction of the staircase frame is generally parallel to the forward edge 16 of the common landing. The staircase frame is supported on the support frame for pivotal movement about a main pivot axis 26 between opposing first and second positions. The pivot axis is horizontal and perpendicular to both the longitudinal direction of the staircase frame and the forward edge of the landing. Furthermore, the pivot axis is centered longitudinally between the opposing first and second ends of the staircase frame.

In the first position, the staircase frame ascends from the first end at the first level to the second end at the second level. Alternatively at the second position, the staircase frame ascends from the second end at the first level to the first end at the second level. Accordingly, in both instances the staircase frame defines a functional stairway from the first level to the second level.

The support frame 24 generally comprises two laterally opposed side frames which are parallel to one another and adjacent laterally opposed sides of the staircase frame. Each side frame includes a base portion 28 fixed relative to the ground or the building structure and an upright portion extending upwardly from the base portion so that the two upright portions 30 are parallel and laterally opposed from one another. The upright portion is located at a longitudinal center of the staircase frame for locating the main pivot axis extending between the upright portions 30 of the two side frames.

The staircase frame 18 generally includes two stringer members 32 which extend the full length of the frame in the longitudinal direction between the opposing first and second ends at laterally opposed sides of the staircase frame so as to be adjacent to respective ones of the side frames of the support frame 24. The stringer members 32 include respective inner sides which are parallel and spaced apart from one another between which a plurality of tread members 34 extend.

Each tread member 34 is pivotally connected at the laterally opposed ends on the respective stringer members 32 for pivotal movement about a respective horizontal tread axis which is perpendicular to the longitudinal direction of the staircase frame such that an upper tread surface 36 of each tread member remains horizontal throughout pivotal movement of the staircase frame relative to the support frame between the first and second positions.

The horizontal orientation of the tread surfaces is maintained by a respective tread linkage in the form of two link members 38 extending in the longitudinal direction of the staircase frame adjacent respective stringer members at laterally opposed sides of the staircase frame. The link members 38 are pivotally connected to respective side frames of the support frame 24 at a central location in the longitudinal direction of the link members such that the two link members are pivotal relative to the support frame about a common horizontal axis extending therebetween. The common pivot axis of the link members relative to the support frame lies in a common vertical plane with the main pivot axis of the staircase frame relative to the support frame.

Each of the tread members 34 further includes a pair of upright leg portions 40 at opposing ends thereof for connection to the laterally opposed link members 38 respectively. All of the tread axes of the tread members 34 relative to the staircase frame lie in a common plane extending in the longitudinal direction of the staircase frame with the leg portions all being pivotally connected to the link members respectively within a second common plane parallel to the longitudinal direction of the staircase frame. In this manner the distance between the tread axis and the pivotal connection of the respective leg portions with the link members is equidistant for all tread members. Accordingly, the two link members and the staircase frame define parallel links of a four bar parallelogram linkage.

The assembly 10 further comprises a railing assembly in the form of two railing members 42 lying in a common plane parallel to the longitudinal direction of the staircase frame at respective laterally opposed sides of the staircase frame. Accordingly, each railing member 42 iies in a substantially common plane with a respective stringer member spaced therebelow. The two railing members 42 are also pivotally connected to respective ones of the laterally opposed side frames of the support frame so as to be pivotal relative to the support frame about a common horizontal axis extending between the two railing members within a common vertical plane with the main pivot axis 26.

The railing assembly further includes two uprights at each of the laterally opposed sides of the staircase frame in which the two uprights a first upright and a second upright. Each first upright 44 is pivotally connected at a bottom end with the first end of the staircase frame and at a top end with the corresponding end of a respective railing member thereabove. Each second upright 46 is pivotally connected at a bottom end on the second end of the staircase frame and pivotally connected at the top end to the other end of the corresponding railing member thereabove. The uprights are all parallel to one another such that the railings and the stringers of the staircase frame therebelow similarly form parallel links of a four bar parallelogram linkage to ensure the railing members remains parallel to the longitudinal direction of the staircase frame as the staircase frame is pivoted between the first and second positions thereof.

The lifting staircase assembly 0 further includes a first load supporting platform 48 supported at the first end of the staircase frame and a second load supporting platform 50 supported at the second end of the staircase frame. In each instance, the platform spans laterally between the pair of uprights at the corresponding end of the staircase frame so as to be joined in fixed perpendicular relationship therewith. Due to the parallelogram linkage of the railing assembly, the uprights remain vertical and the load supporting platforms remain horizontal throughout pivoting movement of the staircase frame relative to the support frame between the first and second positions thereof.

More particularly, the first load supporting platform 48 is horizontal and supported at the first level in the first position while the second load supporting platform is horizontal and supported at the second level in the first position. Alternatively, in the second position of the staircase frame the first load supporting platform 48 is supported at the second level and the second load supporting platform 50 is supported at the first level. Throughout the range of motion of the staircase frame, the platforms 48 and 50 are arranged to support a suitable load thereon for movement therewith between the first and second levels. Loads may include one or more persons, or mobility assisting devices as described above.

Suitable locking members are also typically provided in each instance for securing the load supporting platforms relative to the respective first or second levels in either the first or second positions of the staircase frame. Furthermore, a suitable mechanism is preferably provided for selectively fixing and securing the staircase frame relative to the support frame in both the first position or the second position thereof.

For additional security for the users, a plurality of additional links may extend in the longitudinal direction between the opposing uprights at each side of the staircase frame to partially enclose the space between the railing member and the corresponding stringer member therebelow at each side of the staircase frame. Alternatively, balusters may be connected between the railing members and the respective stringer members therebelow. In either instance, the longitudinal members or the balusters also form a parallelogram linkage with the stringers of the staircase frame to ensure functionality regardless of the position of the staircase frame. The load supporting platforms at opposing ends may also include a railing structure about the perimeter thereof at a location spaced above the upper supporting surface of the respective platforms in the usual manner of a railing. The railings on the load supporting platforms however can simply be fixed relative to the uprights and the respective load supporting platforms and do not require a parallelogram linkage relative to the platforms to remain oriented in a functional manner throughout the pivoting movement of the staircase frame relative to the support frame. Part of the railing structure about each load supporting platform preferably further includes a gate structure to allow entrance and exit of a load onto the respective platform.

One or more corresponding edges of the platform may also be tapered for ease of loading or unloading a load relative to the platform by rolling movement along the ground.

Turning now more particularly to the first and second embodiments of Figures 1 through 6, the tread linkage in this instance is supported below the tread members by pivotally connecting the two link members 38 to the support frame at respective locations spaced vertically below the main pivot of the staircase frame relative to the support frame. In this instance, the leg portions 40 of each tread member extend downwardly from the upper tread surface and the pivotal connection to the stringer members to respective bottom ends which are pivotally connected to the link members respectively.

With regard specifically to the first embodiment of Figures 1 through 5, the lifting staircase assembly 10 further comprises two gas springs 52 which are coupled between the support frame and the staircase frame. The gas springs are arranged to be extended in the second position of the staircase and compressed in the first position sufficiently to produce a biasing force to urge the staircase frame from the first position back towards the second position. The gas springs further provide a dampening function to dampen the movement of the staircase frame as it returns to the first position. The two gas springs pivotally supported at one end on the support frame at laterally spaced positions below the main pivot axis. The gas springs extend generally longitudinally towards an opposing end which is pivotally coupled to the first end of the staircase frame at laterally spaced positions on a common cross bar 54 extending horizontally between the two stringer members.

Due to the biasing force provided by the gas springs 52 which may counterbalance a load on the first platform, movement of the staircase frame between the first and second positions may be reasonably accomplished in a manual manner, for example using a hand crank.

In further embodiments an actuator may be anchored on the support frame and coupled to the staircase frame so as to drive the movement of the staircase frame between the first and second positions thereof. Suitable balancing of the staircase frame about the main pivot axis minimizes the power requirements of the actuator so that a large variety of actuators may be suitable, for example hydraulics, or various types of electrical motors.

Turning now more particularly to the second embodiment of Figure 6 when no gas shocks are provided the second load supporting platform may provide the sole counterbalancing. Alternatively, an additional mass may be supported on the second load supporting platform or otherwise at the second end of the staircase frame to counterbalance a load on the first load supporting platform 48 in relation to the main pivot axis of the staircase frame. Additional counterbalancing mass at the second end of the frame to counterbalance a load on the first platform is desired when lifting is primarily accomplished by the first load supporting platform 48. In this instance, the second load supporting platform need not be moveable together with the staircase frame but may simply remain as part of the landing at the second level so that only the staircase frame and the first load supporting platform are moveable between the first and second positions.

In further arrangements, no counterbalancing of a load is required if a sufficiently powerful actuator is coupled to the staircase frame. If a single platform is provided but the staircase frame is balanced about the main pivot axis, then the actuator supports the load of the platform and a load thereon. If two platforms are provided at opposing ends which are balanced with one another about the main pivot axis of the staircase frame, then the actuator is only relied upon to provide support for the expected load on the platform and the driving force to pivot the staircase frame between the first and second positions. In this instance, each of the two opposing platforms functions equally as a lift between the first and second levels.

Turning now to the third embodiment of Figure 7, the tread linkage in this instance is supported above the tread members by locating the two link members 38 to extend adjacent and above respective ones of the two stringer members of the staircase frame so that the pivotal connection of the two link members 38 is above the main pivot axis of the stringer members. The leg portions 40 of the tread members in this instance extend upwardly from the respective upper tread surfaces to their respective pivotal connections on the link members 38.

Turning now to the fourth embodiment of Figures 8 and 9, the lifting staircase assembly 10 in this instance is similar to the previous embodiments with regard to a staircase frame being pivotally supported on a support frame for movement between first and second positions together with a railing assembly in a parallelogram linkage. Also, similar to the previous embodiments two load supporting platforms are supported at opposing ends of the staircase frame in connection with the parallelogram linkage of the railing assembly to remain horizontal as the staircase is pivoted between the first and second positions.

The fourth embodiment of Figures 8 and 9 differs from the previous embodiments in the configuration of the staircase frame, however, in that the tread members 34 in this instance are integrally connected to the stringers as a common fixed structure moveable together between the first and second positions of the staircase frame relative to the support frame. In the first position, the tread members each define a first tread surface 60 which is an upper horizontal surface of the tread member. The first tread surfaces being interconnected as a staircase by a plurality of respective risers. In the first position, the risers are defined by second tread surfaces 62 which are not functional as treads and are in an upright orientation in the first position. The first tread surfaces 60 thus define the functional stairway in the first position which communicates from the first end of the staircase frame at the first level to the second end of the staircase frame at the second level similarly to previous embodiments.

In the second position of the staircase frame the second tread surfaces 62 become the functional staircase communicating between the first end at the second level and the second end at the first level by being oriented horizontal and spaced apart in the longitudinal direction of the staircase frame. The first tread surfaces 60 are not functional as treads in the second position and are instead in an upright orientation to define respective risers extending between respective ones of the second tread surfaces 62.

The fourth embodiment is generally only suited for applications when the longitudinal direction of the staircase frame is oriented at approximately 45 degrees from horizontal in both the first and second positions.

As described herein, the figures generally illustrate a staircase lift which in accordance with one aspect of the invention comprises a plurality of midsection stairs connecting two substantially horizontal oppositely disposed platforms so that one is distal and one is proximal. In one position, the proximal platform is at ground or a lower level and the distal platform is disposed adjacent to a higher level of floor of the structure. Both platforms may be encased in security railing. The stairs are also provided with safety railings. In the current figures, a balustrade is not shown and is often not provided in outdoor staircases.

Overall, it is to be understood that there are a number of ways to provide security and safety to the use of the device from the provision of very simple hand rails, banisters and balusters to fully or partially enclosed staircase. The present invention is not limited to any one means of providing such security or stair enclosure/containment.

Even in embodiments described above in which the stairs are comprised of treads or step surfaces and risers, the stairs remain 100% functional to an ambulatory user in either orientation (that is an appropriate stair pitch (usually less than 42 degrees) or stair rise to run ratio (e.g. 7: 11 ) is maintained. Nonetheless, the present invention is not intended to be limited to any particular stair pitch or stair rise. In some embodiments, an elegant mechanism may be used to maintain stair geometry (i.e. to maintain stair step surfaces substantially horizontal in either final pivot position) is also shown in various embodiments using a parallel member constructed to link to either end of the main frame structure. Each stair unit (which is the entire step, comprising the tread and the riser) may be pivotably connected to the third parallel member and the lower parallel member. Thus each stair unit is free to pivot during the movement of the entire structure, the linkages operating to keep each unit substantially horizontal at all times. At the final pivot position of the whole structure, the staircase geometry (rise to run ratio) is maintained at the original pitch.

The staircase lift of the present invention is preferably a staircase constructed side-ways adjacent to a landing (for example, the front porch of a house). Either end of the staircase preferably has a platform large enough to accommodate a wheelchair, scooter, stroller, etc. Each platform is preferably pivotally connected to either the top or bottom of the staircase. As such, the stairs, handrails, and vertical platform railings form a parallelogram linkage. The balanced structure can pivot around the centre of the stairs and handrails in the manner of a see-saw with the parallelogram linkage operating to maintain each of the platforms substantially horizontal at all times. A person (e.g. in a wheelchair) would be able to enter either the top or bottom staircase platform and quickly move to the other position. Either platform or the stairs are always ready or available.

In a preferred form, the load is a human user, more preferably a human user with a mobility assistance device selected from the group consisting of a wheelchair, a scooter, stroller, perambulator and personal vehicle. The staircase lift is equally suited for carrying non-human cargo including animals, furniture, groceries and the like.

In a preferred form, the second level is higher than the first level but either way the respective platforms can be raised and lowered between at least two positions. In a further preferred form, the proximal substantially flat load bearing platform and the distal substantially flat load bearing platform include load ingress and egress means, at both first level and second level. Preferably, the staircase lift of the present invention comprises handrails and vertical platform members and wherein stairs, handrails and vertical platform members collectively form a parallelogram linkage.

A key aspect of the present invention is the support of an intermediate portion of the staircase frame on the support frame which allows a balanced upward and downward range of motion at the opposing ends of the staircase frame in a similar manner to a see-saw. The present invention is not limited to any one driving means, as there are a number of means that could be employed to achieve the desired result. Most preferably, the driving of the staircase frame about the main pivot axis in the preferred embodiments operates by way of a pulley system, at least one manual or automatic crank or by way of cantilevered weights. The pivot driver (i.e. levered movement of the staircase lift) may be driven by an external power source, such as an electric, gas or other fuelled motor or it may simply be human powered, by crank or the like, the latter of which offers advantages in the event of a power outage.

Another aspect of the staircase lift of the present invention is its balanced operation. That is, if a counter weight is somehow added to the opposite platform of that typically used by a specific user (i.e. the main occupant of a house would normally always use the same platform), then the structure would be substantially balanced distal/proximal or across both platforms. In this configuration, the power required to raise or lower the lift would be minimal and possibly may be human powered. The energy required to move the structure would simply entail overcoming the frictional forces of the pivots, drive mechanism, and other moving parts.

Another embodiment of the invention occurs when one of the platforms, either the distal or proximal, is not present. Instead a counter weight is in place, perhaps below the last stair unit. In this manner, the staircase lift would still operate as described in the manner of a see-saw, pivoting as described. But now there would only be a single platform to raise an occupant; and the stairs would still be fully functioning in at least one orientation (e.g. when the single platform is in the up position). The staircase lift of the present invention may be applied to any building or structure, including houses and commercial buildings but there are a variety of other applications as well (airports, construction sites, temporary diversions etc . It is preferred that the staircase lift is situated parallel and adjacent to the structure, said structure having at least two levels of entry. Each level corresponds to a floor in a building or structure as shown best in the Figures in which the distal platform is at ground or a lower level and the proximal platform is disposed adjacent to upper landing on a higher level of floor of the structure.

In operation, there is provided a method of conveying a load between a first level and a second level on a structure which comprises securably aligning to and in parallel against the structure a staircase assembly by: placing the load on the distal, substantially flat load bearing platform; activating the pivot means such that the distal, substantially flat load bearing platform is safely raised to a second higher level and concurrently the proximal substantially flat load bearing platform is lowered, in the manner of a see saw; and activating a locking means to hold the distal, substantially flat load bearing platform in position at the second higher level; and removing the load.

It is preferred that the platforms are securably alignable with landings on the structure and that there are means of ingress to and egress from the platforms. These means can take the form of openabie-closable gates, fences, movable railings and the like which provide some degree of retention of the load during platform movement between positions.

Regardless of which platform is in the upper and lower position, the midsection stairs remain in a fully usable state, without any mechanical connection. As such, it is possible that a user may enter a first platform, secure himself/herself on this platform, raise himself/herself using, for example, a cranking means, egress the platform once raised or lowered into the second height position but then later elect to take to the stairs. Using the staircase lift of the present invention, a set of correctly oriented fully functional staircase remains in place at all times. In a preferred form, there are means to lock or hold the load in place on a platform. In one embodiment, the staircase lift may be fully or partially covered from the elements by awning or other protective devices.

While the devices and the methods described herein constitute preferred embodiments of this invention, it is to be understood that the invention is not limited to these precise forms. As will be apparent to those skilled in the art, the various embodiments described above can be combined to provide further embodiments. Aspects of the present device and system, and methods of use (including specific components thereof) can be modified, if necessary, to best employ the systems, methods, nodes and components and concepts of the invention. These aspects are considered fully within the scope of the invention as claimed. For example, the various methods described above may omit some acts, include other acts, and/or execute acts in a different order than set out in the illustrated embodiments. Further, in the methods taught herein, the various acts may be performed in a different order than that illustrated and described. Additionally, the methods can omit some acts, and/or employ additional acts.

These and other changes can be made to the present systems, methods and articles in light of the above description. In general, in the following claims, the terms used should not be construed to limit the invention to the specific embodiments disclosed in the specification and the claims, but should be construed to include all possible embodiments along with the full scope of equivalents to which such claims are entitled. Accordingly, the invention is not limited by the disclosure, but instead its scope is to be determined entirely by the following claims.

Claims

CLAIMS:

1. A lifting staircase assembly for operation between a first level and a second level which is greater in elevation than the first level, the assembly comprising:

a support frame supporting the staircase frame thereon for movement between a first position in which the staircase frame ascends from the first end at the first level to the second end and a second position in which the staircase frame ascends from the second end to the first end at the second level; and

a load bearing platform supported on the first end of the staircase frame for movement therewith between the first position in which the load bearing platform is supported at the first level and the second position in which the load bearing platform is supported at the second level;

the staircase frame defining a longitudinally extending functional stairway between the first and second ends of the staircase frame for providing access between the first and second levels in at least one of the first and second positions of the staircase frame.

2. The assembly according to Claim 1 wherein in said at least one of the first and second positions of the staircase frame the second end of the staircase frame is aligned with a respective one of the first and second levels different from the first end of the staircase frame so as to define a longitudinally extending functional stairway between the first and second levels.

3. The assembly according to either one of Claims 1 or 2 wherein the second end of the staircase frame is at the second level in the first position and wherein the second end of the staircase frame is at the first level in the second position such that the staircase frame defines a longitudinally extending functional stairway between the first and second ends of the staircase frame at respective ones of the levels in both the first and second positions of the staircase frame.

4. The assembly according to any one of Claims 1 through 3 wherein the staircase frame is securable in fixed relation to the support frame in both of the first and second positions.

5. The assembly according to any one of Claims 1 through 4 wherein the staircase frame is supported for pivotal movement relative to the support frame about a horizontal pivot axis oriented perpendicularly to the longitudinal direction of the staircase frame and located at an intermediate location between the first and second ends of the staircase frame.

6. The assembly according to Claim 5 wherein the horizontal pivot axis is longitudinally centered between the first and second ends of the staircase frame.

7. The assembly according to any one of Claims 1 through 6 wherein the staircase frame is supported on the support frame at an intermediate location between opposing ends of the staircase frame and wherein a counterbalance member is supported on the staircase frame adjacent the second end of the staircase frame so as to be arranged to counterbalance the load bearing platform in relation to the intermediate location.

8. The assembly according to any one of Claims 1 through 7 further comprising a linkage coupling the load bearing platform to the staircase frame so as to remain horizontal throughout movement between the first and second positions of the staircase frame.

9. The assembly according to Claim 8 wherein the linkage comprises a link which is parallel to the longitudinal direction of the staircase frame.

10. The assembly according to any one of Claims 1 through 9 further comprising an auxiliary platform supported on the second end of the staircase frame so as to be arranged to support a load thereon for movement with the staircase frame between the first position in which the auxiliary platform is at the second level and the second position in which the auxiliary platform is at the first level.

11. The assembly according to Claim 10 further comprising a horizontal landing supported at the second level, wherein the load bearing platform is aligned with the landing in the second position and the auxiliary platforms is aligned with the landing in the first position.

12. The assembly according to any one of Claims 1 through 11 further comprising:

a railing member pivotally coupled to the support frame at a location spaced above the staircase frame; and

at least one upright pivotally coupled between the railing member and the staircase frame;

the staircase frame being pivotally coupled to the support frame such that the railing member and the staircase frame define a pair of parallel links of a four- bar parallel linkage.

13. The assembly according to Claim 12 wherein said at least one upright comprises a first upright adjacent the first end of staircase frame and wherein the load bearing platform is coupled to the first upright in fixed relation thereto such that the load bearing platform remains horizontal throughout movement of the staircase frame between the first and second positions.

14. The assembly according to any one of Claims 1 through 13 wherein the staircase frame includes a plurality of tread members at spaced apart positions in the longitudinal direction so as to define the stairway between the first and second ends and wherein the tread members define a tread surface which is horizontal is both the first and second positions of the staircase frame.

15. The assembly according to Claim 14 wherein:

the tread members are pivotally coupled to the staircase frame for pivotal movement about respective horizontal axes oriented perpendicularly to the longitudinal direction of the staircase frame;

a link member extends in the longitudinal direction of the staircase frame in pivotal connection with each tread member at a location spaced equidistant from the respective axes of the tread members;

the link member is pivotally coupled to the support frame; and the staircase frame is pivotally coupled to the support frame such that the link member and the staircase frame define a pair of parallel links of a four-bar parallel linkage.

16. The assembly according to Claim 15 wherein the link member is pivotally coupled to the support frame below a pivotal coupling between the staircase frame and the support frame and the link member spans in the longitudinal direction of the staircase frame below the tread surfaces of the tread members.

17. The assembly according to any one of Claims 1 through 16 further comprising a horizontal landing supported at the second level including a forward edge against which the load bearing platform is aligned with in the second position, wherein the longitudinal direction of the staircase is parallel to the forward edge.

18. The assembly according to any one of Claims 1 through 17 further comprising a biasing member coupled between the staircase frame and the support frame so as to be arranged to bias the staircase frame from the first position towards the second position.

19. The assembly according to any one of Claims 1 through 18 in combination with a mobility assistance device selected from the group consisting of a wheelchair, a scooter, stroller, perambulator and personal vehicle.

20. The assembly according to any one of Claims 1 through 19 further comprising an actuator coupled between the staircase frame and the support frame so as to be arranged to drive movement of the staircase frame between the first and second position.

21. A method of conveying a load between a first level and a second level in greater elevation that the first level, the method comprising:

a) providing a lifting staircase assembly comprising:

c) placing a load on the load bearing platform; and

22. The method according to Claim 21 including fixing the staircase frame relative to the support frame at the second position prior to removing the load from the load bearing platform at the second level.

23. The method according to either one of Claims 21 or 22 wherein the staircase frame is supported for pivotal movement relative to the support frame about a main pivot axis between the first and second positions and wherein the method includes supporting a counterbalancing mass on the second end of the staircase frame which substantially counterbalances the load on the load bearing platform about the main pivot axis.

24. The method according to any one of Claims 21 through 22 wherein the staircase frame is supported for pivotal movement relative to the support frame about a main pivot axis between the first and second positions and wherein the method includes providing a biasing force acting on the staircase frame to urge the staircase frame from the first position towards the second position so as to substantially counterbalance the load on the load bearing platform about the main pivot axis.

25. The method according to any one of Claims 21 through 24 including locating the second end of the staircase frame at the second level in the first position such that the staircase frame defines a longitudinally extending functional stairway between the first and second in the first position.

26. The method according to any one of Claims 21 through 25 including locating the second end of the staircase frame is at the first level in the second position such that the staircase frame defines a longitudinally extending functional stairway between the first and second levels in the second position.

27. The method according to any one of Claims 21 through 26 wherein the staircase frame includes a plurality of tread members having upper tread surfaces at spaced apart positions in the longitudinal direction so as to define the stairway between the first and second ends and wherein the method includes maintaining respective upper tread surfaces horizontal throughout movement of the staircase frame between the first and second positions.

28. The method according to any one of Claims 21 through 27 wherein the load is a human user with a mobility assistance device selected from the group consisting of a wheelchair, a scooter, stroller, perambulator and personal vehicle.