US3557504A - Plastic nosing for stairways - Google Patents

Abstract

A PLASTIC STAIR NOSING COMPRISES AN ELONGATED PLASTIC BODY HAVING A NARROW SLOT IN ONE EDGE WHICH EXTENDS SUBSTANTIALLY THE FULL LENGTH OF THE PLASTIC BODY, SO THAT IT IS ADAPTED TO FIT ONTO THE FORWARD LIPPED EDGE OF A METAL PAN STAIR. THE REMAINDER OF THE TREAD PORTION OF THE METAL PAN STAIR COMPRISES CONCRETE OR OTHER FILLER MATERIAL. THE PLASTIC NOSING IS SAFER THAN THE CONVENTIONAL METAL NOSINGS AND NEED NOT BE PAINTED. NO SCREWS, ANCHORS OR WELDING ARE REQUIRED TO HOLD THE NOSING IN POSITION? IT IS SELF-POSITIONING, SELF-LEVELING AND SELF-SUPPORTING.

Description

Jan. 26, 1971 R. H. GRAF PLASTIC NOSING FOR STAIRWAYS 3 Sheets-Shoot 1 Filed Nov. 30, I 1967 n /I/ I I v I M2 Jan. 26, 1971 R. H. GRAF 3,557,504

PLASTIC NOSINGV FOR SIMRWAYS Filed Nov. 50, 1967 v 3 Sheets-Sheet 2 I Jan. 26, 1971 H. GRAF I PLASTIC NOSING FOR STAIRWAYS 3 Sheets-Sheet 3 Filed Nov. 30, 1967 United States Patent 3,557,504 PLASTIC NOSING FOR STAIRWAYS Richard H. Graf, Hauppauge, N.Y., assignor to Hooker Chemical Corporation, Niagara Falls, N.Y., a corporation of New York Filed Nov. 30, 1967, Ser. No. 686,934 Int. Cl. E04d 11/16 Cl. 52-179 6 Claims ABSTRACT OF THE DISCLOSURE A plastic stair nosing comprises an elongated plastic body having a narrow slot in one edge which extends substantially the full length of the plastic body, so that it is adapted to fit onto the forward lipped edge of a metal pan stair. The remainder of the tread portion of the metal pan stair comprises concrete or other filler material.

The plastic nosing is safer than the conventional metal nosings and need not be painted. No screws, anchors or welding are required to hold the nosing in position; it is self-positioning, self-leveling and self-supporting.

BACKGROUND OF THE INVENTION Metal pan stairs are conventionally constructed by providing a metal frame that is comprised of a series of treads and risers. Normally the metal tread has a forward turned-up lip which is the height of the total thickness of the tread-portion of the finished step. In constructing the stairway, after the metal frame is installed, the pan formed by the primary tread and forward turned-up lip is filled in with cement or other filler media, such as terrazzo, to provide secondary treads. The forward lipped edge serves to support the filler medium during the hardening process and also to form a stronger forward edge to the finished step. Moreover, the forward lipped edge can be bent inwardly, toward the secondary tread, to form a leading edge on the finished step. However, it is difficult to retain paint or other surface coatings on such metal nosings. Moreover, the metal nosings readily wear smooth and become a safety hazard to persons ascending and descending the finished stairs.

Accordingly, it is an object of this invention to provide a plastic nosing for stairways, especially metal pan stairs provided with concrete secondary treads.

proved stair construction which includes use of the plastic nosing of the invention.

These and other objects will become apparent upon reference to the following detailed description.

DESCRIPTION OF THE EMBODIMENT The invention will be further described with respect to the accompanying drawings of which FIGS. 1 and 2 are cross-sectional views of a single unit of stair with the plastic stair nosing of the invention in place. FIG. 3 hows a series of stair units as they would appear in a stair construction in cross-sectional view.

FIG. 1 shows a single unit 10 of a finished stair. The metal stair frame is formed by a primary metal pan tread 12 and riser portions 14 extending above and below tread 12. The tread 12 has a forward lipped edge comprised of a forward turned-up lip 16 of a lesser height than the total thickness of the completed step and provided at its upper extremity with an essentially horizontal extension 18. As shown in the figure, a given tread 12 and the vertical riser extending above the tread can be formed from one piece of metal and the forward lipped edge of this 3,557,504 Patented Jan. 26, 1971 tread can be formed by a separate metal portion that comprises the riser 14 extending from the step beneath and running continuously to form the turned up lip 16 and extension 18 as depicted. However, this construction detail is optional and the tread 12, riser 14 turned up edge 16 and extension 18 could be formed from one piece of metal. Stair nosing 20 comprises a slab of polyvinyl chloride or other suitable plastic. Nosing 20 has a narrow slot 22 in the edge of the plastic slab which extends substantially the full length thereof. Generally the plastic nosing is horizontally disposed as shown, with the width of the upper surface being at least about twice the vertical depth of the solid body of plastic. The narrow slot is horizontally disposed in the vertical face of the nosing that serves as the front or leading edge of the stair on which it is installed. This verticle face preferably joins the upper surface in a smooth curved surface, as shown. The vertical rear face 24 can be curved, as shown. In its installed position as shown in FIG. 1, nosing 20 is attached via slot 22 to the metal extension member 18. Forming the remainder of the step and forming the secondary tread thereof is concrete portion 26. In constructing the step, nosing 20 is slipped or snapped into place on extension member 18, which serves to hold nosing 20 in a level position without further support. Thus, no screws, anchors or welding are required to hold the nosing in position. Then, cement is filled in to the side of, and beneath, nosing 20 and leveled off to form a horizontal secondary tread that forms a level surface adjoining the upper surface of the plastic nosing 20.

FIG. 2 shows another single unit 30 of a finished stair. The metal stair frame is formed by a primary metal pan tread 32 and riser portions 34 extending above and below tread 32. The tread 32 has a forward lipped edge comprised of a forward turned-up lip 36 of a lesser height than the total thickness of the completed step. Stair nosing 40 comprises a slab of polyvinyl chloride or other suitable plasitc. In this embodiment, nosing 40 has a narrow slot 42 in the forward portion of the lower edge of the plastic slab, which slot extends substantially the full length of the slab. The narrow slot is vertically disposed in the lower face of the nosing, and is positioned somewhat back of the front face 43 of the nosing, so that the front face extends over, and at least partially covers the forward turned-up lip 36. The front face 43 can extend below the lower face of the nosing, as shown. The front face preferably joins the upper face in a smooth curved surface, as shown. The vertical rear face can be curved, as shown. The upper face can have a series of grooves 45 to improve the non-slipping quality of the nosing. In its installed position as shown in FIG. 2, nosing 40 is attached via slot 42 to the forward turned-up lip 36. The remainder of the step, and forming the secondary tread thereof, is concrete portion 46.

FIG. 3 shows a series of stair units in place, with step or stair unit 10 being substantially as described with respect to FIG. 1. Stair unit is a typical unit adapted to serve as the top step of a stair construction so that it properly adjoins the floor or roof at the top of the stairs. Thus, primary metal pan tread 52 can be suitably connected such as by welding or otherwise to a metal subfloor 53. The concrete secondary tread 56 can be made to be level with a concrete floor portion 57. Stair unit 60 represents a typical unit adjoining the floor at the bottom of a stair construction. Riser 64 extends downwardly from stair section 60 and is aifixed by any suitable means to the supporting floor 65.

The preferred type of plastic for use as the stair nosing of the invention is polyvinyl chloride. However, other normally solid, thermoplastic materials can be used. Other suitable thermoplastics include the polyolefins, such as polyethylene, poly-propylene, copolymers of ethylene with higher olefins polystyrene, thermoplastic butadiene polymers and copolymers, such as butadiene-styrene block copolymers, and other polythenic compositions such as polyvinyl chloride-acetate copolymer, polyvinylidene chloride, acrylic polymers and the like.

The plastic nosing of the invention can be produced in conventional extruder in which the plastic. material is softened or melted and extruded through an orifice having the shape of the desired cross-section of the plastic nosing. In this regard, the cross-sectional shapes shown in FIGS. 1 and 2 are intended to be illustrative, but not to limit the invention. Thus, for example, the vertical edge at the opposite side of the nosing from the narrow slot 22 can have various shapes. As shown in FIG. 3, this face can have a diagonal flat face 66 that is slanted downward toward the rear of the stair or a square groove in a vertical face 54 or a curved face 67, as well as curved face 24 and a variety of other curved shapes. Moreover, the lower, horizontally disposed face of the nosing can be exactly parallel to the uppermost face or can be diagonally disposed as shown in FIGS. 1, 2 and 3. The edge of the nosing that forms the leading edge of the entire stair is preferably curved to form a smooth transition from the horizontal upper face to the vertical edge that fits atop the forward lipped edge 16 and extension member 18 or forward lipped edge 36. Other variations of the invention are possible without departing from the underlying principals of the invention. It is understood that the foregoing embodiments are intended to be illustrative of the invention but not to limit it.

I claim:

1. A stair construction comprised of one or more stair units comprising a metal riser portion and a step portion, said step portion comprising a metal primary pan tread having a forward turned-up lip of less height than the total thickness of the step, a plastic nosing comprising an elongated plastic body having a width of at least about twice the thickness thereof and having a narrow slot in one face of said plastic body and extending substantially the full length thereof, which slot is engaged onto said turned-up lip so as to maintain the upper surface of said plastic body in a substantially horizontal position; and a secondary tread which fills the cavity formed by the primary metal pan tread and said plastic nosing.

2. In a metal pan stair construction, the improvement which comprises a plastic nosing comprising an elongated plastic body having a width of at least twice the thickness thereof and having a narrow slot in one face of said plastic body and extending substantially the full length thereof, said narrow slot engaged onto the forward lipped edge of the metal pan tread of said metal pan stairs so as to maintain said plastic nosing in substantially horizontal position.

3. A stair construction comprised of one or more stair units comprising a metal riser portion and a step portion; said step portion comprising a metal primary pan tread having a forward turned-up lip of less height than the total thickness of the step wherein said lip has a metal extension member protruding from its upper extremity; a plastic nosing comprising an elongated plastic body having a width of at least about twice the thickness thereof and having a narrow slot horizontally disposed in a vertically disposed face of said plastic nosing and extending substantially the full length thereof, which slot is engaged onto said extension member so as to maintain the upper surface of said plastic body in a substantially horizontal position, and wherein said vertically disposed face joins the horizontally disposed uppermost face of said plastic nosing in a curved surface; and a secondary tread which fills the cavity formed by said primary metal pan tread and said plastic nosing.

4. The stair construction of claim 3 wherein the plastic is polyvinyl chloride.

5. A stair construction comprised of one or more stair units comprising a metal riser portion and a step portion; said step portion comprising a metal primary pan tread having a forward turned-up lip of less height than the total thickness of the step; a plastic nosing comprising an elongated plastic body having a width of at least about twice the thickness thereof and having a narrow slot vertically disposed in the lower face of the said plastic nosing, which slot extends substantially the full length thereof and which slot is engaged onto said turned-up lip so as to maintain the upper surface of said plastic body in a substantially horizontal position, and wherein the vertically disposed face adjacent said narrow slot joins the horizontally disposed uppermost face of said plastic nosing in a curved surface; and a secondary tread which fills the cavity formed by said primary metal pan tread and said plastic nosing.

6. The stair construction of claim 5 wherein the plastic is polyvinyl chloride.

References Cited UNITED STATES PATENTS 1,545,181 7/1925 Bechtel 52-188 1,557,285 10/1925 Hughes 52179 1,674,713 6/1928 Brooks 52179 2,654,919 10/1953 Marvin 52-716X 3,334,456 8/1967 Naka 52179 FOREIGN PATENTS 222,295 1959 Australia 52-179 1,266,664 1961 France 52-181 586,409 1947 Great Britain 52179 JOHN E. MURTAGH, Primary Examiner US. Cl. X.R. 52181

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