GB2499779A

GB2499779A - Stairway with strings and adjustable pitch

Info

Publication number: GB2499779A
Application number: GB1200790.2A
Authority: GB
Inventors: Alistair Wright
Original assignee: TWO TWENTY Ltd
Current assignee: TWO TWENTY Ltd
Priority date: 2012-01-18
Filing date: 2012-01-18
Publication date: 2013-09-04
Also published as: GB201200790D0

Abstract

A staircase 10 comprises a plurality of treads 12, and strings 14. The treads 12 extend between the strings 14 to form a stairway. Each tread 12 is attached to the strings 14 by pivotal arrangements providing a pivot axis 36. Each tread 12 can pivot relative to the strings 14 through an arc 42. This allows the staircase to be reconfigured by the treads moving between a use position in which the treads and strings together form a stairway, and a stowed position, in which the treads are parallel with the strings. The pivotal attachment arrangements also allow the staircase to be installed with a range of different pitches for the stairway. The strings may be in two parts (14a 14b Fig. 7) and be hinged together (52 Fig. 7). A riser 22 may be provided between each tread and may be pivotally adjustable about a pivot 26.

Description

1

Improvements in or relating to staircases The present invention relates to improvements in or relating to staircases.

5

Staircases are commonly manufactured off-site, for transport to the installation location. Accordingly, the manufacture of the staircase is based on measurements taken at the installation location, or on building plans. It is found that there are only small tolerances possible within this process, to ensure that the steps of the staircase are level when 10 installed. For example, errors in measurement, errors in plans or errors in construction from the plans can result in the staircase being unusable, even when errors are as small as 10 mm or 20 mm. In that event, the staircase must be returned off-site, to be modified or fully remanufactured, or alternatively, neighbouring structures must be modified, which can be time consuming and thus costly.

15

Examples of the present invention provide a staircase comprising:

a plurality of treads;

20 first and second strings, the treads extending between the strings to form a stairway; and attachment arrangements attaching the treads to the strings;

25 wherein the attachment arrangements are adjustable in accordance with the pitch of the stairway.

The attachment arrangements may be pivotally adjustable. Each end of each tread may be pivotally attached to a string by means of an attachment arrangement. The 30 attachment arrangement may comprise a pivot arrangement around which a tread is

2

pivotable relative to a string, and a releasable fixing arrangement operable to fix the orientation of the tread, relative to the string.

The attachment arrangements may allow the treads to move between a use position, in 5 which the treads and strings together form the stairway, and a stowed position, in which the treads are aligned more closely with the length of the string than when in the use position. The treads may lie parallel with each other and with the length of the string, when in the stowed position.

10 The strings may each comprise first and second string members extending along the length of the string and hingedly connected together, the treads being attached to the first string member, the second string member being hingeable to a stowed position against the treads, when the treads are in their stowed position.

15 The staircase may further comprise at least one riser adjustably attached to a first tread to extend from the first tread to an adjacent tread over a range of pitches of the stairway. The riser may be pivotally attached to the first tread. The riser may extend to the tread below. Substantially all of the treads may have an associated riser, as aforesaid.

20

Examples of the present invention also provide a staircase comprising:

a plurality of treads; and

25 first and second strings, the treads extending between the strings to form a stairway;

the staircase further comprising at least one attachment arrangement which allows the staircase to be reconfigured from a use condition to a more compact

30 condition.

3

The attachment arrangement may allow the staircase to be reconfigured by the treads moving between a use position, in which the treads and strings together form a stairway, and a stowed position. The treads may be aligned more closely with the length of the string when in the stowed position than when in the use position. The treads may 5 lie parallel with each other and with the length of the string, when in the stowed position.

The attachment arrangements may be pivotally adjustable. Each end of each tread may be pivotally attached to a string by means of an attachment arrangement. The attachment arrangement may comprise a pivot arrangement around which a tread is 10 pivotable relative to a string, and a releasable fixing arrangement operable to fix the orientation of the tread, relative to the string.

The strings may each comprise a plurality of string members attached by attachment means which allow the string members to be reconfigured from a use condition to a 15 more compact condition. The strings may each comprise first and second string members extending along the length of the string. The string members may be hingedly connected together. The treads may be attached to the first string member, the second string member being hingeable to a stowed position against the treads, when the treads are in their stowed position.

20

The staircase may further comprise at least one riser adjustably attached to a first tread to extend from the first tread when in the use condition, and able to move relative to the first tread to a more compact condition. The riser may be pivotally attached to the first tread. The riser may extend to the tread below, when in the use condition. Substantially 25 all of the treads may have an associated riser, as aforesaid.

Examples of the invention also provide a method of installing a staircase, comprising:

installing first and second strings at an angle;

30

4

installing a plurality of treads extending between the strings, to form a stairway, the pitch of the stairway being set by the angle at which the strings are installed;

wherein the treads are attached to the strings by attachment arrangements which are adjustable to accommodate a range of stairway pitches.

5

The staircase may have any of the features or combinations of features set out above.

Examples of the present invention will now be described in more detail, by way of 10 example only and with reference to the accompanying drawings, in which:

Fig. 1 is a perspective view of a staircase;

Fig. 2 is an end view of a step of the staircase of Fig. 1;

15

Fig. 3 is a partial section at 3-3 of the staircase of Fig. 1;

Figs. 4, 5 and 6 are sections at 4, 5,6-4,5,6 of the staircase in various conditions;

and

20

Fig. 7 is an end view of the staircase in the fully collapsed condition.

Overview

25 Fig. 1 illustrates part of a staircase 10 installed to provide a stairway within a building. In this description, the term "staircase" is used to refer to the apparatus being installed, both before and after installation. The term "stairway" is used to refer to the facility provided by the staircase, once installed.

30 The staircase 10 comprises a plurality of treads 12, and first and second strings 14. The treads 12 extend between the strings 14 to form a stairway. The strings 14 are installed

5

at an angle 16 to the horizontal 18. That is, the length 20 of the strings 14, and the horizontal 18, together define the angle 16. The angle 16 is known as the "pitch" of the stairway and is a characteristic of the stairway, rather than the staircase 10, because the angle 16 depends on the installation of the strings 14.

5

Attachment arrangements will be described for attaching the treads 12 to the strings 14. The attachment arrangements are adjustable in accordance with the pitch of the stairway.

10 When the staircase 10 is installed, in a manner which will be described, the treads 12 provide horizontal upper surfaces used for climbing up the stairway. In this example, the gap between each tread 12 and the adjacent treads 12 (above and below) is closed by a riser 22.

15 The attachment arrangements, which will be described, also allow the staircase to be reconfigured from a use condition to a more compact condition.

Step construction

20 Each tread 12, and an associated riser 22, together form a step 24 for the staircase 10 (Fig. 2). Fig. 2 shows a step 24, comprising a tread 12 to which a riser 22 is attached by means of a hinge 26. The hinge 26 allows the riser 22 to adopt a stowed position indicated at 28, or to hinge away from the step 24 through an arc 30 of intermediate positions 32 any of which may be used as a use position. The angle of the arc 30 is

25 determined by the construction details of the hinge 26. In this example, the angle of the arc 30 is greater than 90°. That is, the riser 22 can hinge from the stowed position 28 through intermediate positions 32 to a final position 34, which is past the perpendicular to the tread 12.

6

When in the use position, the riser 22 extends from the tread 12, but the attachment provided by hinge 26 allows the riser 22 to move relative to the tread 12 to the stowed position which is a more compact condition for riser 22 and step 24.

5 Fig. 2 also shows the position of a pivot axis 36 for the tread 12, the significance of which is described below.

Attachment arrangements for the treads io Each tread 12 has an associated pivot axis 36, as noted above. This defines the pivot axis of the adjustable attachment between the tread 12 and the strings 14. Each end of each tread 12 is pivotally attached to a respective string 14 by means of an attachment arrangement which, in this example, comprises a pivot arrangement around which the tread 12 is pivotable relative to the string 14. The pivot arrangements at each end of the 15 same tread 12 define the same pivot axis 36. Examples of pivot arrangements include pivot pins, dowels etc formed by, or attached to one of the components, and received in a socket in the other. Fig. 3 is a partial detail section showing a pivot pin 38 mounted in the end of a tread 12 and received in a socket 40 in the string 14, to allow the tread 12 to be pivotable relative to the string 14, about the axis 36.

20

Accordingly, each tread 12 can pivot relative to the strings 14 through an arc 42 of positions. The angle of the arc 42 is determined by the construction details of the pivots between the tread 12 and the strings 14. In this example, the angle of the arc 42 is at least 42 degrees. This allows the treads 12 to move between various positions, some of 25 which are illustrated in Figs. 4, 5 and 6. Fig. 4 and Fig. 5 show two alternative use positions in which the surface 44 of the tread 12, which will form the upper horizontal surface of the tread 12 when the staircase is installed, lies at different angles to the length 20 a string 14.

7

Fig. 6 shows a stowed position in which the treads 12 are aligned more closely with the length 20 of the strings 14. In this example, the treads 12 lie parallel with each other and with the length 20 of the strings 14, when in the stowed position.

5 The pivotal attachment arrangements allow the staircase to be reconfigured by the treads moving between a use position in which the treads and strings together form a stairway, as noted above, and a stowed position, in which the staircase is in a more compact condition, as can be seen from Fig. 6.

10 A releasable fixing arrangement indicated generally at 46 is provided at each end of each tread 12, to fix the orientation of the tread 12, relative to the strings 14. In this example, the fixing arrangement 46 includes a series of bores 48 in the strings 14, for receiving a peg 50, on which the tread 12 rests. Consequently, the angle of the tread 12, relative to the length 20 of the strings 14 when in the use position,, is determined by 15 the choice of bore 48 in which the pegs 50 are located.

Figs 4, 5 and 6 also show risers 22 in various positions relative to the treads 12. In Fig. 4 and Fig. 5, the risers 22 are shown in two different extended positions. That is, the arc 30 through which the risers 22 have swung in Fig 5 is different (slightly larger) than the 20 arc 30 through which the risers 22 have swung in Fig. 4. Thus, each riser 22 extends from the tread 12 to which it is attached, to the tread below. In Fig. 6, the risers 22 are in their stowed position discussed above in relation to Fig. 2.

Folding strings

25

The strings 14 each comprise first and second string members 14a, 14b which extend along the length of the string 214. The string members 14a, 14b are connected together by an attachment arrangement in the form of a hinge at 52, defining a hinge axis extending along the string 14, parallel to the length 20 of the string 14. The treads 30 12 are mounted on the first string member 14a and, when in their stowed position (Fig.

8

6), lie entirely to that side of the hinge 52. When swung out to one of the use positions (Fig 4 or Fig 5, for example), the treads 12 straddle the line of the hinge 52.

Consequently, when the treads 12 are all in their stowed positions, the second string 5 member 14b can hinge to a stowed position illustrated in Fig. 7, in which the string member 14b lies against the stowed risers 22.

This allows string members to reconfigured from their use condition to a more compact condition (Fig. 7).

10

Installation

When the staircase 10 is to be installed to provide a stairway, the staircase 10 is first constructed as described, which can conveniently be effected off-site. The staircase 10 15 can then be put into its more compact condition by folding the treads 12 and risers 22 to their stowed conditions. The staircase 10 can be further compacted by folding down the second string members 14b, putting the staircase 210 in the compact condition illustrated in Fig. 7. The staircase 10 can then be transported to the installation site in its compact condition. The compactness achieved in this way will facilitate transport 20 and is expected to reduce transport costs.

Once at the installation site, the staircase is reconfigured to its use condition. To achieve this, the string members 14b are folded out to their use positions, and the staircase 10 is fixed into position by installing the strings 14 at an angle to the 25 horizontal. This sets the pitch of the stairway being provided. The chosen pitch angle is determined by the building in which the staircase 10 is being installed. The staircase 10 can be installed to accommodate a range of tolerances in measurement or construction, by adjustment of the angle at which the strings 14 are installed.

30 Once the strings 14 have been installed, the treads 12 are pivoted from their stowed positions (Fig. 6) to an appropriate use position selected so that the upper surface 44 of

9

each tread 12 is at or acceptably close to horizontal. The use position is selected by the fixing arrangement 46. It can be understood, particularly from consideration of Fig. 4 and Fig. 5 that the pivotal arrangement of the treads 12 allows them to accommodate a range of stairway pitches, while still providing horizontal steps in the finished stairway.

5

Once the treads 12 have been installed in their finished position, the risers 22 are swung to span down to the tread 12 below, and secured in position by appropriate catches or other arrangement (not shown).

10 Concluding comments

The treads 12 can accommodate various different stairway pitches, as noted above. Furthermore, the risers 22 can also accommodate various different stairway pitches, by adopting various different angles relative to the treads 12. However, it is envisaged that 15 the range of angles at which the risers 22 may finally be installed will not differ from the vertical by an amount such as to be noticeable to the user, other than by close observation. Risers 22 are traditionally vertical, but that could give rise to gaps between a riser 22 and the adjacent tread 12, depending on the stairway pitch. Gaps of this nature are likely to be more noticeable than the orientation of a riser as being slightly 20 away from the vertical.

In a typical installation, a staircase 10 having strings 14 of length 3600mm might be installed to provide a total staircase height between 2500mm and 2800mm by installing the strings 14 to provide a stairway pitch between about 35 degress and 42 degress. 25 With a typical rise height of approximately 200mm to 220mm and a typical tread depth of 220mm to 245mm, any departure of the risers 22 from the vertical is unlikely to be apparent by eye.

Accordingly, a staircase constructed as described above is expected to be useful for 30 installation over a range of total staircase heights and in particular, to be adjustable to accommodate variations typically found in practice as a result of measurement errors,

10

building plan errors or building construction errors, without requiring any remanufacturing of the staircase. This avoids wasted costs, wasted time and unnecessary transport.

5 Many variations can be made to the apparatus described above, without departing from the scope of the invention. Elements of the staircase can be manufactured from various different materials. Manufacture from timber is envisaged. Many different arrangements can be envisaged for providing the pivotal connections, for securing the various components in relative positions and in other respects. Risers could be omitted, while 10 still leaving the treads adjustable relative to the strings.

Whilst endeavouring in the foregoing specification to draw attention to those features of the invention believed to be of particular importance it should be understood that the Applicant claims protection in respect of any patentable feature or combination of 15 features hereinbefore referred to and/or shown in the drawings whether or not particular emphasis has been placed thereon.

11

Claims

1. A staircase comprising:

5 a plurality of treads;

first and second strings, the treads extending between the strings to form a stairway; and

10 attachment arrangements attaching the treads to the strings;

wherein the attachment arrangements are adjustable in accordance with the pitch of the stairway.

CO

■^—15 2. A staircase according to claim 1, wherein the attachment arrangements are i pivotally adjustable.

o

O) 3- A staircase according to claim 1 or 2, wherein each end of each tread is pivotally attached to a string by means of an attachment arrangement.

20

4. A staircase according to any preceding claim, wherein the attachment arrangement comprises a pivot arrangement around which a tread is pivotable relative to a string, and a releasable fixing arrangement operable to fix the orientation of the tread, relative to the string.

25

5. A staircase according to any preceding claim, wherein the attachment arrangements allow the treads to move between a use position, in which the treads and strings together form the stairway, and a stowed position, in which the treads are aligned more closely with the length of the string than when in the use position.

30

12

6. A staircase according to claim 5, wherein the treads lie parallel with each other and with the length of the string, when in the stowed position.

7. A staircase according to claim 5 or 6, wherein the strings each comprise first and second string members extending along the length of the string and hingedly connected together, the treads being attached to the first string member, the second string member being hingeable to a stowed position against the treads, when the treads are in their stowed position.

8. A staircase according to any preceding claim, further comprising at least one riser adjustably attached to a first tread to extend from the first tread to an adjacent tread over a range of pitches of the stairway.

9. A staircase according to claim 8, wherein the riser is pivotally attached to the first tread.

10. A staircase according to claim 8 or 9, wherein the riser extends to the tread below.

11. A staircase according to claim 8, 9 or 10, wherein substantially all of the treads have an associated riser, as aforesaid.

12. A staircase comprising:

a plurality of treads; and first and second strings, the treads extending between the strings to form a stairway;

13

the staircase further comprising at least one attachment arrangement which allows the staircase to be reconfigured from a use condition to a more compact condition.

5 13. A staircase according to claim 12, wherein the attachment arrangement allows the staircase to be reconfigured by the treads moving between a use position, in which the treads and strings together form a stairway, and a stowed position.

14. A staircase according to claim 13, wherein the treads are aligned more closely 10 with the length of the string when in the stowed position than when in the use position.

15. A staircase according to claim 14, wherein the treads lie parallel with each other and with the length of the string, when in the stowed position.

CO

■^—15 16. A staircase according to any of claims 12 to 15, wherein the or each attachment arrangement is pivotally adjustable.

o

CD 17. A staircase according to any of claims 12 to 16, wherein each end of each tread is pivotally attached to a string by means of an attachment arrangement.

20

18. A staircase according to any of claims 12 to 17, wherein the attachment arrangement comprises a pivot arrangement around which a tread is pivotable relative to a string, and a releasable fixing arrangement operable to fix the orientation of the tread, relative to the string.

25

19. A staircase according to any of claims 12 to 18, wherein the strings each comprise a plurality of string members attached by attachment means which allow the string members to be reconfigured from a use condition to a more compact condition.

30 20. A staircase according to claim 19, wherein the strings each comprise first and second string members extending along the length of the string.

14

21. A staircase according to claim 19 or 20, wherein the string members are hingedly connected together.

5 22. A staircase according to claim 19, 20 or 21, wherein the treads are attached to the first string member, the second string member being hingeable to a stowed position against the treads, when the treads are in their stowed position.

23. A staircase according to any of claims 12 to 22, further comprising at least one 10 riser adjustably attached to a first tread to extend from the first tread when in the use condition, and able to move relative to the first tread to a more compact condition.

24. A staircase according to claim 23, wherein the riser is pivotally attached to the first tread.

1—15

25. A staircase according to claim 23 or 24, wherein the riser extends to the tread O below, when in the use condition.

CD

26. A staircase according to claim 23, 24 or 25, wherein substantially all of the treads 20 have an associated riser, as aforesaid.

27. A staircase substantially as described above, with reference to the accompanying drawings.

25 28. A method of installing a staircase, comprising: installing first and second strings at an angle;

30

15

29. A method according to claim 28, wherein the staircase is a staircase according to any of claims 1 to 27.

30. A method of installing a staircase, substantially as described above, with reference to the accompanying drawings.

31. Any novel subject matter or combination including novel subject matter disclosed herein, whether or not within the scope of or relating to the same invention as any of the preceding claims.