Patent Description:
The present invention generally relates to the field of stair systems. More specifically, embodiments provided herein relate to moveable stairs, including connectors, joints, devices, and configurations for allowing rotational, longitudinal, directional, and/or differential movements between levels or landings, and within stair structures to provide safe egress, enhance rescue, and/or reduce damage during movement.

In multi-level buildings and structures stairs are essential to not only providing a means for moving about the levels but also for providing safe egress out of the structure in the event of an emergency. As such, stair safety is a constant concern as taller buildings continue to be constructed of new and more efficient materials and in various locations around the globe. The construction and installation of stairs create a necessary exit path that is regulated by various building codes which oftentimes require the stairs to survive fire and structural damage such that occupants can safely exit the building during a state of emergency.

Conventional stair assemblies, however, are rigidly connected to a landing or building structure rather than dynamically connected to a landing or building structure. As such, typical stair assemblies do not allow for sufficient movement in the event of building motion (e.g., during a seismic event, high winds, explosions, etc.). Rigidly connected stairs create a force that must be accounted for in the building design. Furthermore, due to the interstory drift that occurs during building motion, rigidly connected stair systems can cause damage to any of the surrounding structure, the area below the stair system, and/or the stair system itself. Rigidly connected stairs can disconnect, crumble, fail, and/or fall during building motion, which prohibits occupants from safely exiting, delays rescue operations, and threatens safety. Moreover, due to interstory drift and the forces generated through a building during building motion, rigidly connected stairs may cause damage to themselves and the surrounding structure, thus causing the structure to perform differently than originally engineered. The results can further include structural damage surrounding the stairs, or partial or total collapse of the stairs. Any damage to and/or collapse of the stair system immediately eliminates a means of egress from the building and places the occupants therein in additional danger during or after a building motion event and/or emergency. Injury or loss of life is also possible depending on the extent of the damage.

Moreover, attempts to solve these problems have been made, but many do not complete full-scale testing, or meet applicable building codes, regulations, and/or project requirements. Prior systems also are not designed or intended to accommodate rotation of the stairs during building movement. <CIT> discloses a stair expansion joint system with freedom of movement between landings. <CIT> discloses moveable stair systems and methods.

Thus, stair safety and installation can increase building safety and reduce the effects of building motion. Therefore, what is needed in the art is a moveable stair system and method. More specifically, what is needed is a rotational connection for stairs which allows for rotational movement, longitudinal movement, multidirectional movement, and/or orbital capacity to absorb landing displacement thus reducing damage to the stairs.

The present invention relates to systems for allowing stair movement, including rotational movement, between building levels while maintaining the structural integrity of the stair system for safe egress passage. The systems and methods of the present disclosure allow for independent movement of the surrounding building walls, landings, floor slabs, and/or any other portion of the surrounding building structure or stair system. The embodiments of the present disclosure are suitable for use in both new constructions as well as in existing constructions for retrofit applications to allow for movement between levels, landings, or within stairwell structures. Moreover, the embodiments of the present disclosure apply to both single and double stringer stairs. The present disclosure can reduce stair damage during building movement whether it is from wind, thermal, explosive, or seismic activity, and/or any other type of suitable force or experience, as the present disclosure allows at least for rotational movement and longitudinal movement, directional movement, or a combination thereof.

In accordance with the present invention, an apparatus suitable for use with a stair system is defined in claim <NUM>.

In some embodiments, the single-point connection device includes at least one of a shaft configuration, a pin-type configuration, a nut-and-bolt configuration, a ball-and-socket configuration, a hitch-type configuration, a ball-joint-rod-end configuration, a swivel joint configuration, or a configuration in which one or more structural shapes fit together. In certain embodiments, the secondary movement connection device comprises a first face having a slot therein, and, in some embodiments, the single-point connection device is at least partially disposed through the slot to operatively connect the secondary movement connection device with the single-point connection device. In some embodiments, the single-point connection device is centrally located within the first face.

Also in accordance with the present invention, a moveable stair system is defined in claim <NUM>.

In some embodiments, the single-point connection device includes at least one of a shaft configuration, a pin-type configuration, a nut-and-bolt configuration, a ball-and-socket configuration, a hitch-type configuration, a ball-joint-rod-end configuration, a swivel joint configuration, or a configuration in which one or more structural shapes fit together. In certain embodiments, the secondary movement connection device includes a first face having a slot therein. The single-point connection device can at least be partially disposed through the slot to operatively connect the secondary movement connection device with the single-point connection device. In some embodiments, the single-point connection device is centrally located within the first face. In certain embodiments, the secondary movement connection device includes a slotted connector, a track system connector, a guide rail connector, a wheeled connector, a roller connector, a slide connector, or a plate connector. In some embodiments, the moveable stair system also includes a landing plate configured to cover a gap disposed between the staircase and a first landing. In certain embodiments, the first landing connection system is further operatively connected to a first landing.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and are intended to provide further explanation of the disclosed subject matter claimed.

So that the manner in which the above recited features of the present disclosure can be understood in detail, a more particular description of the disclosure, briefly summarized above, can be had by reference to embodiments, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only exemplary embodiments and the invention is defined by the claims.

To facilitate understanding, identical reference numerals have been used to designate identical elements that are common to the figures. It is contemplated that elements and features of one embodiment can be beneficially incorporated in other embodiments without further recitation.

The present invention generally relates to stair systems and methods for allowing stair movement, including rotational movement, between building levels while maintaining the structural integrity of the stair system for safe egress passage. The systems and methods of the present disclosure allow for independent movement of the surrounding building walls, landings, floor slabs, and/or any other portion of the surrounding building structure or stair system. The embodiments of the present disclosure are suitable for use in both new constructions as well as in existing constructions for retrofit applications to allow for movement between levels, landings, or within stairwell structures. Moreover, the embodiments of the present disclosure apply to both single and double stringer stairs; a double stringer embodiment is used in the accompanying drawings for purposes of illustration only. Furthermore, the term "stair" or "stairs" means a series of risers and treads adjacent to or between stringers. The term "stairs" or "staircase" further includes the definition, meaning, and use of the term "stair assembly. " The present disclosure can reduce stair damage during building movement whether it is from wind, thermal, explosive, seismic activity, and/or any other type of suitable force or experience, as the present disclosure allows for rotational movement, longitudinal movement, or a combination thereof.

Reference will now be made in detail to various exemplary embodiments of the invention, examples of which are illustrated in the accompanying drawings where <FIG> show an embodiment of the invention and <FIG> show further features of specific embodiments of the invention. The examples are not intended to limit the scope of the disclosed subject matter in any manner. The disclosed subject matter will be described in conjunction with the detailed description of the system. For purpose of illustration, and not limitation, <FIG>, <FIG>, and <FIG> each schematically illustrate a first landing connection system <NUM> of a stair system <NUM>. In some embodiments, the first landing connection system <NUM> is disposed between a stair or staircase <NUM> and a landing <NUM>. In some embodiments, the landing <NUM> is an upper landing, while in other embodiments the landing <NUM> is a lower landing. In other embodiments, however, a first landing connection system <NUM> can be operatively connected with an upper landing and a lower landing. The first landing connection system <NUM> includes a single-point connection device <NUM>. The single point connection device <NUM> can include any of, by way of example only, a shaft configuration, a pin-type configuration, a nut-and-bolt configuration, a ball-and-socket configuration, a pin-type configuration, a ball-joint-rod-end configuration, a swivel joint configuration, a configuration in which one or more structural shapes fit together, or any other suitable configuration which provides for a single point connection. Upon connection with a stair or staircase <NUM>, the single-point connection device <NUM> allows for rotational movement. The rotational movement includes movement in an X-direction and in a Y-direction. In some embodiments, movement in the X-direction is movement in the transverse direction or side-to-side movement. In some embodiments, movement in the Y-direction is movement in the longitudinal direction or back-and-forth movement.

As further shown in <FIG>, the single-point connection device <NUM> can include a coupler <NUM> and a cross channel <NUM>. The cross channel <NUM> is disposed adjacent the single-point connection device <NUM>. The coupler <NUM> and the cross channel <NUM> can operatively connect the first landing connection system <NUM> with the landing <NUM> and/or staircase <NUM>. In some embodiments, the cross channel <NUM> is U-shaped, however, any suitable shape can be utilized. In some embodiments, the coupler <NUM> is a part of the single-point connection device <NUM> and receives the mating end of the single-point connection device <NUM>. In some embodiments, and by way of example only, a positive connection is made via a pin configured to secure a ball into an acceptor. The pin, ball, and acceptor accommodate rotation and push the X and Y movements to the opposing connection.

The first landing connection system <NUM> includes a base plate <NUM> for connection with the landing <NUM>, as shown in <FIG> and <FIG>, for example. Connection with the landing <NUM> can be made via any suitable connections means, for example, a bolted means. In some embodiments, one or more extenders <NUM> extend in an outward direction from the baseplate <NUM>. As further shown in <FIG> and <FIG>, by way crossbar <NUM> extends between the one or more extenders <NUM>. The crossbar <NUM> includes a midpoint C. The single-point connection device <NUM> is centrally located proximate midpoint C within the first landing connection system <NUM>.

For purpose of illustration and not limitation, <FIG>, <FIG>, and <FIG> each schematically illustrate a second landing connection system <NUM> of the stair system <NUM>. In some embodiments, the second landing connection system includes at least one secondary movement connection device <NUM>. In some embodiments, the secondary movement connection device <NUM> includes a first face <NUM> with a slot <NUM> therethrough. The secondary movement connection device <NUM> is configured to be operatively connected with a stair or staircase <NUM> via any suitable connection, for example, a bolted connection. Further, in some embodiments, the secondary movement connection device <NUM> is configured for longitudinal movement in at least one direction, for example, in at least one of the X-direction and the Y-direction. In some embodiments, movement in the X-direction is movement in the transverse direction, or side-to-side movement, while movement in the Y-direction is movement in the longitudinal direction, or back-and-forth movement. As such, upon connection of the staircase <NUM> with the secondary movement connection device <NUM>, the staircase is moveable in the longitudinal direction upon application of a force thereon.

In some embodiments, the at least one secondary movement connection device <NUM> includes a slotted connector, a track system connector, a guide rail connector, a wheeled connector, a roller connector, a slide connector, or a plate connector.

<FIG> schematically illustrates the stair system <NUM>. As shown, the first landing connection system <NUM>, shown in phantom, operatively connects an upper landing <NUM> with a staircase <NUM>. Furthermore, the second landing connection system <NUM>, shown in phantom in <FIG>, operatively connects a lower landing <NUM> with the staircase <NUM>. In certain embodiments, however, the first landing connection system <NUM> can operatively connect the lower landing <NUM> with the staircase <NUM>, and the second landing connection <NUM> can operatively connect the upper landing <NUM> with the staircase <NUM>.

For purpose of illustration and not limitation, <FIG> each schematically illustrate features of a stair system <NUM>. The stair system <NUM> includes a first landing connection system <NUM>. In some embodiments, the first landing connection system <NUM> is disposed between a stair or staircase and a landing. In some embodiments, the landing is an upper landing, while in other embodiments the landing is a lower landing. In certain embodiments, however, a first landing connection system <NUM> can be operatively connected with an upper landing and a lower landing. However, in some embodiments, the first landing connection system <NUM> can be operatively connected with a single landing whether it be an upper landing or a lower landing. The first landing connection system <NUM> includes a single-point connection device <NUM>. The single point connection device <NUM> can include any of, by way of example only, a shaft configuration, a pin-type configuration, a nut-and-bolt configuration, a ball-and-socket configuration, a pin-type configuration, a ball-joint-rod-end configuration, a swivel joint configuration, a configuration in which one or more structural shapes fit together, or any other suitable configuration which provides for a single point connection. Upon connection with a stair or staircase, the single-point connection device <NUM> allows for rotational movement. The rotational movement includes movement in an X-direction and in a Y-direction. In some embodiments, movement in the X-direction is movement in the transverse direction, or side-to-side movement, while movement in the Y-direction is movement in the longitudinal direction, or back-and-forth movement.

In some embodiments, the first landing connection system <NUM> can include a coupler or a cross channel, as described further herein for embodiments shown in <FIG>. The cross channel is disposed adjacent the single-point connection device <NUM>. The coupler and the cross channel can operatively connect the first landing connection system <NUM> with the landing and/or staircase. In some embodiments, the cross channel is U-shaped, however, any suitable shape can be utilized.

In some embodiments, the first landing connection system <NUM> includes a base plate <NUM> for connection with the landing. Connection with the landing can be made via any suitable connections means, for example, a bolted means. In some embodiments, one or more extenders <NUM> extend in an outward direction from the baseplate <NUM>. As shown in <FIG>, by way of example only, the one or more extenders <NUM> are I-beams. In certain embodiments, the first landing connection system <NUM> includes a secondary movement connection system <NUM>. The secondary movement connection system <NUM> includes a crossbar <NUM>. The crossbar <NUM> extends between the one or more extenders <NUM>. In certain embodiments, the crossbar <NUM> is coupled with the one or more extenders <NUM>, for example, via a bolted connection, a welded connection, or any other suitable connection means. In some embodiments, the crossbar can be a face, plate, beam, rail, or any other suitable device. The crossbar <NUM> includes a midpoint C. According to the invention, the single-point connection device <NUM> is centrally located proximate midpoint C within the first landing connection system <NUM>.

As further illustrated in <FIG>, for the purpose of illustration and not limitation, the secondary movement connection device <NUM> also includes a first face <NUM> of the crossbar <NUM>. The first face <NUM> includes a slot <NUM> therein. In some embodiments, the slot <NUM> can extend through the first face <NUM> or through the crossbar <NUM>. In certain embodiments, the slot <NUM> can extend in the longitudinal director, in the lateral direction, or in an approximately diagonal direction. In some embodiments, the single-point connection device is at least partially disposed through the slot to operatively connect the secondary movement connection device <NUM> with the single-point connection device <NUM>, such that the single point connection device <NUM> is configured to move in the direction of the slot <NUM>. As such, upon connection of a staircase with a landing via the stair system of <FIG>, the staircase is moveable in a rotational direction-in a combination of an X-direction and a Y-direction-as well as in a longitudinal direction-in at least one of the X-direction and the Y-direction. In some embodiments, movement in the X-direction is movement in the transverse direction, or side-to-side movement, while movement in the Y-direction is movement in the longitudinal direction, or back-and-forth movement.

For purpose of illustration and not limitation, <FIG> schematically illustrates a moveable stair system <NUM>. The moveable stair system includes a staircase <NUM> having one or more stairs <NUM>. The first landing connection system <NUM> as discussed with reference to <FIG>, supra, is disposed at a first end <NUM> of the staircase <NUM>, wherein the first end <NUM> is opposite a second end <NUM>. In some embodiments, the first landing connection system <NUM> is operatively connected with a first landing <NUM> via any suitable connection means. The first landing connection system <NUM> includes the single-point connection device <NUM> and the secondary movement connection device <NUM>. The staircase <NUM> is operatively connected with the first single-point connection device <NUM>. In some embodiments, the first landing connection system <NUM> includes a landing plate. The landing plate is operatively disposed to cover a gap between the staircase <NUM> and the first landing <NUM>. In some embodiments, a second end <NUM> of the staircase <NUM> can rest on the landing or floor <NUM>, or in other embodiments, the second end <NUM> of the staircase <NUM> can be operatively connected with the landing or floor <NUM> via any suitable connection means.

Exemplary benefits of stair systems in accordance with the disclosed subject matter include that the stair system allows for rotational movement to absorb landing displacement reducing damage to the stair system, thus allowing for safe egress. Furthermore, the disclosed connection means for connecting a staircase with a landing allows for the staircase to rotate, thus accommodating interstory drift in response to an event causing the structure to shake or move (i.e., earthquake, high winds, explosions, etc.). The present disclosure allows stairs the freedom to move to reduce force transfers to unsupported areas of a building, to maintain the structural integrity of the stairs during and after an event to allow for safe egress of occupants and safe ingress of emergency services to later allow for reoccupation of the building. Additionally, the stair systems disclosed are easily disposed at the top or bottom of a flight of stairs, thus allowing all movement to be located at one point (e.g., an intermediate landing) as opposed to requiring each axis of movement to be located at opposite ends of the flight. As such, one end of the flight of stairs can remain fixed or free and yet still provide the benefits of rotational movement. Additionally, testing has been performed and results indicate that, during movement events, stairs tend to naturally move in a rotational direction. As such, the rotational movement permitted by the systems of the present disclosure reduces the risk of damage not only to the stairs or building, but also to adjacent architecture and structural components.

The stair systems and methods disclosed allow for stair movement between building levels, platforms, landings, or the like while maintaining the structural integrity of the stair system for safe egress passage. The systems and methods disclosed further allow for independent movement of the surrounding building walls, landings, floor slabs, and/or any other portion of the surrounding building structure to the stair system. The
embodiments of the present disclosure are suitable for use in both new constructions as well as in existing constructions for retrofit applications to allow for movement between levels, landings, or within stairwell structures. The present invention can reduce stair damage during building movement whether it is from wind, thermal, or seismic activity, and/or any other type of suitable force or experience, as the present invention allows for rotational movement, longitudinal movement, directional movement, or a combination thereof.

Claim 1:
An apparatus suitable for use in a stair system (<NUM>), comprising:
a first landing connection system (<NUM>) comprising:
two or more extenders;
a single-point connection device (<NUM>) configured to allow for rotational movement, wherein the rotational movement is movement in a combination of an X-direction and a Y-direction; and
a secondary movement connection device (<NUM>) operatively connected with the single-point connection device (<NUM>) and configured for longitudinal movement in at least one of the X-direction and the Y-direction,
wherein the secondary movement connection device (<NUM>) includes a crossbar (<NUM>) which extends between said two or more extenders (<NUM>), and
wherein the single-point connection device is located proximate to a midpoint of the crossbar.