GB2179979A - Stair constructions - Google Patents

Abstract

A staircase is composed of modular tread members (2) each having bosses (6) at the front end rear centrally of their width for pivot shafts (14) that interconnect the tread members so that they are adjustable both vertically and pivotally. The shafts can be separated from the tread members for compact storage when the staircase is dismantled. The tread members have laterally tapered top faces which can serve as tread surfaces. <IMAGE>

Description

SPECIFICATION Stairconstructions This invention relates to stair constructions, and in pa rticu larto on nstructions, especially modular con - structions, in which a series of individual prefabricated tread members can be assembledtogetherto form a staircase. The term "tread member" as used herein includes not only a member that itselfforms the stairtread, butalso-a member that has a horizontal face (typically of smaller plan area) on which a planar tread is secured.

In such constructions, a series of identical tread members may each have an integral interconnection element projecting vertically from itto be secured to associated engagement means on a succeeding tread member. Theforms of interconnection is often one which allows relative rotation betwen two members about a vertical axis, so that a spiral staricase can be formed.

According to one aspect ofthe present invention, there is provided a staircase composed of a series of tread members secured together by interconnecting means, each individual tread member being adjustable both vertically and pivotally about a vertical axis with respect to the interconnecting means securing it to each of the tread members preceding and succeeding it.

In a staircase according to the invention it is possibleto adjustthe heightand angle of each tread member individually relative to its neighbours. Furthermore, the interconnecting means can be arranged to be releasable so that the staircase can be dismantled and assembled in different configurations. If the interconnecting means are separable from the tread members, it is possibleto give each tread membera very small vertical dimension so thatthe dismantled members can be stored and transported using relatively little space.

According to another aspect ofthe invention, there is provided a modulartread memberfora staircase, comprising a planar portion and respective apertures on parallel axes at front and rear regions ofthe planar portion, said apertures each having a uniform crosssection forming an axially and rotationally adjustable mounting for interconnecting meansforassembling a pluralityofthetread members into a staircase.

The invention will be described byway of example with reference to the accompanying diagrammatic drawings, in which: Fig. lisa side view illustrating the assembly ofa numberofmodulartread members according to the invention, Fig. 2 is a vertical section ofthe interconnection between two tread members, Fig. 3 illustrates the different modesofadjustment provided by the interconnection means, Figs 4 and 5 i ILustratefurthler details ofthe staircase employingthetread members of the earlierfig u res, and Fig. 6 is a plan ofview illustrating the construction of a spiral staircase according to the invention.

The staircase of the drawings comprise a series of modular tread members 2 of cast metal. Each member has a generally planarbody4with two bosses6 on vertical centre lines in a central plane of symmetry of the body. The bosses are set at the front and rear edges 8, 10 ofthe body, these edges tapering at an angle of 1 5"to a transverse plane of symmetry, projections from these edges intersecting the axes of the bosses. Each boss has an open-ended aperture in the form of a circular bore 12. Each adjacent pair of members is interconnected by a pivot shaft 14that projects through the aligned bores ofthe lower member front boss and the upper member rear boss.

The shaft may be a length oftubing and the members are fixed to it by locking screws 16 driven through topped holes in the bosses. For extra security recesses 18 may be drilled in the shaftsforthe ends ofthe screws.

The top and bottom of a staircase constructed in the manner shown can be held in placebyfixing brackets.

Fig. 4 illustrates a floor bracket22, provided with a boss 24 in the closed bore of which a pivot shaft 14 is held to mount the first tread member 2 of the staircase.

A similar fixing arrangement (not shown) may be used atthe head ofthe staircase. At the foot andthe head of the staircase, at least two, angularly spaced locking screws are used to lockthe associated shafts in position, but at other locations single locking screw will usually be sufficient; As the staircase is assembled, each tread member can be set to a desired angle relative to the preceding memberanditsheightrelativetothatmembercan also be chosen. For the sake of appearance, extendable coversleeves (not shown), for example in the form of corrugated gaiters, can conceal the shafts and their attachment.

Adjustments are possible after assembly ofthe staircase. In particular by slackening offthe locking screws 16 of any individual tread member, that member can be moved up and down relative to its neighbours and the length of the shaft need not prevent reduction ofthe rise between tread members as any surplus can be left projecting below the connecting boss ofthe lower member. It will be clear that the method offixing also leaves the staircase fully demountable andthatthe components can be reused to provide staircases of different configurations to match any particular requirement.

The tread members 2 may have integral tread surfacesoftheform describedbuta more adaptable arrangement is possible if they merely provide supportfacesfor separate treads. They need then have a smaller plan area than the stairtreads, as is shown in Fig. 5 where tapered treads 26 with a plan form such as that shown in Fig. 3 are attached to members 28 having rectangular plan-form bodies by screws 30. In this arrangement the cast metal tread members 28 provide very simple and economical load-bearing means and the treads can be produced in a wide variety of materials and forms to meet the required functional and aesthetic needs. The tapered form oftread illustrated is particularly adapted for a spiral staircase as is apparent from Fig. 6, the taper of each edge avoiding overlap ofthe treads; it will be understood thatthe same modular members can be used for both right-handand left-hand spirals.

Although not illustrated, itis also possible to provide a staircase according to the invention with a handrail. For example metal rods may be screwed into threaded holes at the outer margins of the treads, each rod having an eye, e.g. ofthe slip-on type, at its upper end to support a handrail offlexible or rigid material.

The threaded holesforthe rods would be provided at both lateral edges ofthe threads so that a rail can be mounted at either or both sides.

Claims (15)

1. A staircase composed of a series of tread members secured together by interconnecting means, each individual tread member being adjustable both vertically and pivotably about a vertical axis with respect to the interconnecting means securing it to each of the tread members preceding and succeeding it.

2. Astaircase according to claim 1 wherein the said interconnecting means are releasable for disman- tling the staircase.

3. A staircase according to claim 2 wherein the interconnecting means comprise vertical connecting membersthat are separable fromthetread members.

4. A staircase according to any one of claims 1 to 3 wherein extendable cover means are provided far the interconnection means between adjacent tread members.

5. Astaircase according to any one ofthe preceding claims wherein said interconnecting means are disposed centrally ofthe width of the respective tread members.

6. Astaircase accordingto any one ofthe preceding claims wherein each tread member comprises integral sockets for its interconnection to succeeding and preceding members.

7. Astaircase according to claim Stogetherwith claim 6 whereinthe plan area of each tread member corresponds to the tread surface ofthe stair and the horizontal depth ofthetread members tapers laterally from a central zone oftheirwidth.

8. Amodulartreadmemberforastaircase, comprising a planar portion and respective apertures on parallel axesatfrontand rearregionsoftheplanar portion, said apertures each having a uniform crosssection forming an axially and rotationally adjustable mounting for interconnecting means for assembling a plurality ofthe tread members into a staircase.

9. Atread member according to claim 8 wherein respective bosses providing said apertures project upwardlyfrom the front ofthe planar portion and downwardly from the rear of the planar portion.

10. Atread member according to claim 9 wherein the apertures have a circular cross-section and the bosses are provided with releasable locking means for securing connecting members within the apertures.

11. Atread member according to any one of claims 8to 10wherein the horizontal depth of the planar portion tapers laterally from a central zone atwhich said apertures are disposed.

12. Atread member according to any one of claims 8 to 11 provided with attachment means for a hand rail at regions laterally remote from said apertures.

13. Atread member according toclaim 12wherein said attachment means are provided at both opposite lateral edge regions of the planar portion.

14. A staircase constructed and arranged for use substantially as described herein with reference to the accompanying drawings.

15. Amodulartread memberforastaircase, constructed and arrangedfor use substantially as described herein with reference to the accompanying drawings.