Laterally Collapsible Staircase

Abstract

A laterally collapsible staircase with first and second side rails has a number of advantages compared to prior structures. A leveling screw is connected to the second side rail bottom surface to adjust the position of the stairs when deployed to insure that the stairs are horizontal. The second rail has a top side edge extending between its top and bottom and a recessed area extends along the second rail top side edge allowing a user's fingers to grip the rail to facilitate its movement between laterally collapsed and deployed positions. At least one permanent magnet is connected to the second side rail inner surface capable of interacting with another aligned permanent magnet mounted in a wall to help maintain the second side rail in a laterally collapsed position until intentionally moved. Pre-calibrated gas struts eliminate racking, jiggle, and bounce of the staircase.

Description

BACKGROUND AND SUMMARY OF THE INVENTION

Laterally collapsible staircases have successfully been used for decades in houses and other facilities that have space limitations that make a permanent staircase impractical. Some of many examples may be found in the following patents: FR 827,211 (1938), DE 682,831 (1939), FR 2,136,959 (1971), FR 2,653,148 (1991), DE 4,416,426 (1995), FR 3,004,202 (2013), EP 3,848,527 (2020), and U.S. Pat. No. 10,889,993 (2021). In all of these situations the laterally collapsible staircase has a first side rail and a second side rail parallel to the first side rail. The side rails are operatively connected by a number of steps pivotally connected to the rails. The first side rail is fixedly attachable (and in use attached) to a wall and the second side rail is pivotally movable about the first side rail between a deployed use position in which the steps extend essentially horizontally between the side rails, and a laterally collapsed position in which the steps extend essentially vertically between the side rails.

While many of these laterally collapsible staircases are eminently suitable for numerous situations, oftentimes there are some practical problems associated with them. For example, a) sometimes it is difficult to insure that the stairs are truly horizontal, rather than slanting, when the staircase is in the deployed position; b) many times it is difficult to properly grasp the second side rail to move the staircase between the laterally collapsed and deployed positions; c) sometimes it is difficult to maintain the staircase in the collapsed position while still allowing easy deployment thereof; and d) there can be racking, jiggling, and/or bouncing of the staircase. According to the present invention each of these problems a)-d) is dealt with and solved in a practical manner.

According to one aspect of the present invention it is possible to adjust the staircase in the deployed use position so that regardless of idiosyncrasies of the facility (e. g. house, cabin, plant, warehouse, ship) in which it is installed the steps can be level (e. g. essentially true horizontal), solving problem a), above. The second (movable) side rail has top and bottom surfaces and according to the invention at least one conventional leveling screw with enlarged foot is operatively connected to the second side rail bottom surface to allow adjustment of the position of the stairs when the side rails are in the deployed position to insure that the stairs are substantially horizontal. According to this aspect of the invention the laterally collapsible staircase further comprises at least one conventional leveling screw with enlarged foot operatively connected to the second side rail top surface to allow adjustment of the position of the top surface of the stairs when the side rails are in the deployed position to further insure that the stairs are horizontal.

According to another aspect of the invention the problem of effective gripping of the second side rail to move the staircase from the laterally collapsed to the deployed position is also dealt with, solving problem b) above. The second rail has a top side edge extending substantially between the top and bottom surfaces thereof, and the invention further comprises a recessed area along the second rail top side edge allowing a user's fingers to grip the second rail to facilitate easy movement of the second side rail between the laterally collapsed and deployed positions. Desirably, but not necessarily, the recessed area extends substantially the entire length of the second rail top side edge. Making the movement of the staircase even more practical, according to the invention the second side rail top surface also has a recessed area allowing a user's fingers to grip the second rail at the top thereof to facilitate movement of the second side rail between the laterally collapsed and deployed positions.

According to yet another aspect of the invention, the problem c) above, retaining the staircase in the laterally collapsed position, is also dealt with and solved. The second side rail has an inner surface facing the first side rail, and the invention further comprises at least one (preferably two, one near the top the other near the bottom) permanent magnet operatively connected to the inner surface capable of interacting with another aligned permanent magnet mounted in a wall to which the laterally collapsible staircase is connected to help maintain the second side rail in the laterally collapsed position until intentionally moved from it. The staircase in use is provided in combination with a wall to which the first side rail is attached, and there is at least one permanent magnet mounted in or to the wall positioned to cooperate with the at least one permanent magnet connected to the second side rail to help maintain the second side rail in the laterally collapsed position until intentionally moved from that position.

Also, the staircase of the invention utilizes one or more balanced pre-calibrated gas struts pivotally connected at each end thereof between the bottoms of one or more steps and the first (stationary in use) side rail. These gas struts, especially where two or more are provided, greatly contribute to the sturdiness of the staircase in the deployed position and can actually eliminate racking, jiggle, and bounce of the staircase that can occur, as indicated by problem d) above. [While gas cylinders in this environment are known per se at 13 in FR 3,004,202, there is no indication that they are pre-calibrated or can substantially eliminate racking, jiggle, and bounce of the staircase as can the gas struts of the invention.]

It is the primary object of the present invention to provide an enhanced version of the decades old concept of a laterally collapsible staircase for use in a facility where a permanent staircase is undesirable. This and other objects of the invention will become clear from a detailed description of the invention and from the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an isometric schematic view of an exemplary laterally collapsible staircase according to the invention in a laterally collapsed position;

FIG. 2 is a view like that of FIG. 1 showing the staircase in the deployed use position.

FIG. 3 is a view like that of FIG. 2 with a different orientation and with the wall removed for clarity of illustration;

FIG. 4 is a view like that of FIG. 2 with a different orientation and having circles indicating where leveling screws according to the invention are desirably provided;

FIG. 5 is a detail isometric view showing an exemplary leveling screw associated with the bottom of the second (movable) side rail of the staircase of the invention, the leveling screw at the top of the second side rail being substantially identical; and

FIG. 6 is an isometric schematic view of a groove on the top of the second (movable) rail of the invention being accessed by a user's fingers to effect movement thereof between the laterally collapsed and deployed use positions.

DETAILED DESCRIPTION OF THE DRAWINGS

FIGS. 1 & 2 schematically show a laterally collapsible staircase 10 according to the present invention. The staircase 10 comprises a first (stationary in use) side rail 12 and a second (movable) side rail 14 substantially parallel to the first side rail 12. The second side rail has top and bottom surfaces 16, 18, respectively. The rails 12, 14 are operatively connected by a plurality of steps 20 pivotally connected (by pivot connections 22 similar to hinges) to the rails 12, 14. The first side rail 12 is fixedly attachable to a wall W (and is shown attached thereto by a plurality of conventional fasteners 24 in FIGS. 1 & 2) and the second side rail 14 is pivotally movable about the first side rail 12 between a deployed use position (FIG. 2) in which the steps 20 extend substantially horizontally between the side rails 12, 14, and a laterally collapsed position (FIG. 1) in which steps 20 extend substantially vertically between the side rails 12, 14.

According to the invention at least one conventional leveling screw 28 with enlarged foot 29 (see FIG. 5) is operatively connected to the second side rail 14 bottom surface 18 (as indicated by the bottom circle in FIG. 4) to allow adjustment of the position of the stairs when the rails 12, 14 are in the deployed position to insure that the stairs are substantially horizontal. By screwing the leveling screw 28 in-and-out of the bottom surface 18 of the movable rail 14, the position of the rail 14 can be adjusted to insure the level nature of the steps 20.

The laterally collapsible staircase 10 according to the invention preferably further comprises at least one conventional leveling screw 28 with enlarged foot 29 (essentially the same as shown in FIG. 5) operatively connected to the second side rail top surface 16 (as shown by the top circle in FIG. 4) to allow adjustment of the position of the top surface 16 of the stairs when the side rails 12, 14 are in the deployed use position (FIGS. 2-4) to insure that the stairs 20 are substantially horizontal.

FIGS. 1 & 2 also show two balanced pre-calibrated gas struts 31 each pivotally connected at the ends thereof to the bottom 32 of a step 20 and the first (stationary in use) side rail 12. These pre-calibrated (depending upon the weight and other characteristics of the staircase 10) gas struts 31, especially where two or more are provided, greatly contribute to the sturdiness of the staircase 10 in the deployed position (FIGS. 2-4) and actually can substantially eliminate racking, jiggle, and bounce of the staircase 10.

According to another aspect of the present invention movement of the staircase 10 between its collapsed-(FIG. 1) and deployed use (FIGS. 2-4) positions is facilitated. The second (movable) rail 14 has a top side edge 34 extending substantially between the top and bottom surfaces 16, 18 thereof. Movement of the second rail 14 is facilitated by providing a recessed area 36 (FIG. 3) along second rail top side edge 34 allowing a user's fingers to easily grip the second rail 14 to facilitate movement thereof between the laterally collapsed (FIG. 1) and deployed (FIGS. 2-4) positions. As shown in FIG. 3 the recessed area 36 preferably (although not necessarily) extends substantially the entire length of the second rail top side edge 34.

To facilitate deployment of the staircase 10 when a user is positioned in an area above the staircase 10, according to the present invention the second side rail top surface 16 also has a recessed area 38 (FIG. 6) allowing a user's fingers F (as schematically shown in FIG. 6) to grip the second rail 14 to facilitate movement thereof between the laterally collapsed (FIGS. 1 & 6) and deployed (FIGS. 2-4) positions.

According to yet another aspect of the present invention a mechanism is provided to facilitate retention of the staircase 10 in the laterally collapsed position of FIG. 1 while still allowing it to be effectively and easily moved to the deployed use position of FIGS. 2-4. The second side rail 14 has an inner surface 42 (FIG. 3) facing the first side rail 12. Retention of the staircase 10 in the collapsed position (FIG. 1) is accomplished by desirably providing at least one permanent magnet 44 (two shown in FIG. 3) operatively connected to (e. g. countersunk in) the inner surface 42 capable of interacting with another aligned permanent magnet 46 (see FIG. 4) mounted in a wall W to which the laterally collapsible staircase 10 is connected to help maintain the second side rail 14 in the laterally collapsed position of FIG. 1 until intentionally moved from that position. For example the magnets 44 can have their N poles facing the wall W while the magnets 46 have their S poles facing the surface 42.

The invention also comprises the staircase 10 as described above in combination with the wall W to which the first side rail 12 is attached, with at least one permanent magnet 46 mounted in or to the wall W (e. g. countersunk in the wall W) positioned to cooperate with the aligned at least one permanent magnet 44 connected to the second side rail 14 to help maintain the staircase 10 in the laterally collapsed position (FIG. 1) until intentionally moved from that position.

While the magnets 44, 46 are highly preferred to perform the retention function described above, other known or hereinafter developed means for performing the retention function can be provided, such as aligned strips or tabs of cooperating hook and loop fasteners held with effective adhesive to the surface 42 and wall W.

Other structures may also be provided with the staircase 10 according to the invention such as, but not limited to, railings connected to the wall W (as in FR 3,004,202) and/or to the movable rail 14 (as in FR 827,211 or DE 4,416,426). Alternatively, or in addition, a movable gate (as shown in FR 2,653,148) may be provided connected to the top of the movable side rail 14 to prevent someone from inadvertently falling when the staircase 10 is not deployed.

The staircase 10 of the invention is not limited by any dimensions or number or extent of stairs 20, the staircase 10 being able to be constructed to correspond to a large number of different facilities having different specific requirements.

While the invention has been herein shown and described in what is presently conceived to be the most practical and preferred embodiments thereof it is to be understood that the invention is to be accorded the broadest interpretation of the appended claims to cover all equivalent mechanisms and structures, limited only by the prior art.

Claims

1. A laterally collapsible staircase comprising: a first side rail and a second side rail substantially parallel to said first side rail, said second side rail having top and bottom surfaces;said rails operatively connected by a plurality of steps pivotally connected to said rails;said first side rail fixedly attachable to a wall and said second side rail pivotally movable about said first side rail between a deployed use position wherein said steps extend substantially horizontally between said side rails, and a laterally collapsed position wherein said steps extend substantially vertically between said side rails; andat least one leveling screw with enlarged foot operatively connected to said second side rail bottom surface to allow adjustment of the position of said stairs when said side rails are in said deployed position to insure that said stairs are substantially horizontal.

2. A laterally collapsible staircase as recited in claim 1 further comprising at least one leveling screw with enlarged foot operatively connected to said second side rail top surface to allow adjustment of the position of said top surface of said stairs when said side rails are in said deployed position to insure that said stairs are substantially horizontal when deployed.

3. A laterally collapsible staircase as recited in claim 1 wherein said second rail has a top side edge extending substantially between said top and bottom surfaces thereof; and further comprising a recessed area along said second rail top side edge allowing a user's fingers to grip said second rail to facilitate movement of said second side rail between said laterally collapsed and deployed positions.

4. A laterally collapsible staircase as recited in claim 3 wherein said recessed area extends substantially the entire length of said second rail top side edge.

5. A laterally collapsible staircase as recited in claim 2 wherein said second side rail top surface has a recessed area allowing a user's fingers to grip said second rail to facilitate movement of said second rail between said laterally collapsed and deployed positions.

6. A laterally collapsible staircase as recited in claim 1 wherein said second side rail has an inner surface facing said first side rail; and further comprising at least one permanent magnet operatively connected to said inner surface capable of interacting with another permanent magnet mounted in a wall to which said laterally collapsible staircase is connected to help maintain said second side rail in said laterally collapsed position until intentionally moved therefrom.

7. A laterally collapsible staircase as recited in claim 6 in combination with a wall to which said first side rail is attached, and at least one permanent magnet mounted in or to said wall positioned to cooperate with said at least one permanent magnet connected to said second side rail to help maintain said second side rail in said laterally collapsed position until intentionally moved therefrom.

8. A laterally collapsible staircase as recited in claim 3 wherein said second side rail has an inner surface facing said first side rail; and further comprising at least one permanent magnet operatively connected to said inner surface capable of interacting with another permanent magnet mounted in a wall to which said laterally collapsible staircase is connected to help maintain said second side rail in said laterally collapsed position until intentionally moved therefrom.

9. A laterally collapsible staircase as recited in claim 8 in combination with a wall to which said first side rail is attached, and at least one permanent magnet mounted in or to said wall positioned to cooperate with said at least one permanent magnet connected to said second side rail to help maintain said second side rail in said laterally collapsed position until intentionally moved therefrom

10. A laterally collapsible staircase comprising: a first side rail and a second side rail substantially parallel to said first side rail, said second side rail having top and bottom surfaces;said rails operatively connected by a plurality of steps pivotally connected to said rails;said first side rail fixedly attachable to a wall and said second side rail pivotally movable about said first side rail between a deployed position wherein said steps extend substantially horizontally between said side rails, and a laterally collapsed position wherein said steps extend substantially vertically between said side rails;wherein said second rail has a top side edge extending substantially between said top and bottom surfaces thereof; andfurther comprising a recessed area along said second rail top side edge allowing a user's fingers to grip said second rail to facilitate movement of said second side rail between said laterally collapsed and deployed positions.

11. A laterally collapsible staircase as recited in claim 10 wherein said recessed area extends substantially the entire length of said second rail top side edge.

12. A laterally collapsible staircase as recited in claim 10 wherein said second side rail top surface has a recessed area allowing a user's fingers to grip said second rail to facilitate movement of said second rail between said laterally collapsed and deployed positions.

13. A laterally collapsible staircase comprising: a first side rail and a second side rail substantially parallel to said first side rail, said second side rail having top and bottom surfaces;said rails operatively connected by a plurality of steps pivotally connected to said rails;said first side rail fixedly attachable to a wall and said second side rail pivotally movable about said first side rail between an deployed position wherein said steps extend substantially horizontally between said side rails, and a laterally collapsed position wherein said steps extend substantially vertically between said side rails;wherein said second side rail has an inner surface facing said first side rail; andfurther comprising at least one permanent magnet operatively connected to said inner surface capable of interacting with another aligned permanent magnet mounted in a wall to which said laterally collapsible staircase is connected to help maintain said second side rail in said laterally collapsed position until intentionally moved therefrom.

14. A laterally collapsible staircase as recited in claim 13 in combination with a wall to which said first side rail is attached, and at least one permanent magnet mounted in or to said wall positioned to cooperate with said at least one aligned permanent magnet connected to said second side rail to help maintain said second side rail in said laterally collapsed position until intentionally moved therefrom.

15. A laterally collapsible staircase as recited in claim 13 further comprising at least two balanced pre-calibrated gas struts, each pivotally connected at one end thereof to the bottom of a step and pivotally connected at the other end thereof to the first side rail so as to substantially eliminate racking, jiggle, and bounce of the staircase.

16. A laterally collapsible staircase as recited in claim 1 further comprising at least two balanced pre-calibrated gas struts, each pivotally connected at one end thereof to the bottom of a step and pivotally connected at the other end thereof to the first side rail so as to substantially eliminate racking, jiggle, and bounce of the staircase.

17. A laterally collapsible staircase as recited in claim 10 further comprising at least two balanced pre-calibrated gas struts, each pivotally connected at one end thereof to the bottom of a step and pivotally connected at the other end thereof to the first side rail so as to substantially eliminate racking, jiggle, and bounce of the staircase.

18. A laterally collapsible staircase as recited in claim 3 further comprising at least two balanced pre-calibrated gas struts, each pivotally connected at one end thereof to the bottom of a step and pivotally connected at the other end thereof to the first side rail so as to substantially eliminate racking, jiggle, and bounce of the staircase.

19. A laterally collapsible staircase as recited in claim 12 further comprising at least two balanced pre-calibrated gas struts, each pivotally connected at one end thereof to the bottom of a step and pivotally connected at the other end thereof to the first side rail so as to substantially eliminate racking, jiggle, and bounce of the staircase.

20. A laterally collapsible staircase as recited in claim 7 further comprising at least two balanced pre-calibrated gas struts, each pivotally connected at one end thereof to the bottom of a step and pivotally connected at the other end thereof to the first side rail so as to substantially eliminate racking, jiggle, and bounce of the staircase.