AU649566B2

AU649566B2 - A carpet hold down strip

Info

Publication number: AU649566B2
Application number: AU26150/92A
Authority: AU
Inventors: Keith Vanderliet
Original assignee: BHP Steel JLA Pty Ltd
Current assignee: SANKEY AUSTRALIA Pty Ltd
Priority date: 1991-10-04
Filing date: 1992-10-01
Publication date: 1994-05-26
Anticipated expiration: 2012-10-01
Also published as: AU2615092A

Description

649566 P/00/011 Regulation 3.2

AUSTRALIA

Patents Act 1990

ORIGINAL

COMPLETE SPECIFICATION STANDARD PATENT Invention Title: "A CARPET HOLD DOWN STRIP" a 0 The following statement is a full description of this invention, including the best method of performing it known to the Applicant:- This invention relates to carpet hold down strips, that is to say toothed strips which are fixed to the floor of a room to be carpeted adjacent to its walls, and which engage the margin of the carpet to enable the carpet to be stretched across the floor area and ensure that it 5 remains so.

Such strips are well known and widely used. Traditionally they have comprised a timber lath with a plurality of nails piercing the lath, with the nail points protruding from the upper side therenf. In use the 2 lath is fixed to the floor and the carpet is engaged by the protruding nails.

In attempts to reduce the cost of carpet laying it has been proposed to provide hold down strips fabricated from sheet metal. Such sheet metal strips have comprised an inverted channel sectioned strip with upwardly directed teeth punched from the web of the channel, In use the strip rests upon the edges of the channel flanges and may be secured to the floor by fasteners extending through clearance holes in the web.

In all instances, the teeth are inclined rather than vertical, and in use the strip is set so that the points of the teeth are directed towards the wall. Thus, a carpet may be placed with an edge against a wall and a margin overlying a hold down strip adjacent to the wall. If the carpet is then stretched away from the wall, the teeth bite into it to prevent its edge from moving away from the wall, and, due to their inclination, simultaneously draw the carpet down onto the strip. Therefore, for so long as the carpet remains in tension, the strips hold it firmly in place.

0t Hitherto, each tooth of metal hold down strips has been shaped as an isosceles triangle extending inclinedly upwardly from the base line of S 20 the triangle (along which the tooth is united to the channel web) to the apex of the triangle (constituting the pointed end of the tooth). That is to say, each tooth has been a triangle of sheet metal lying in an inclined plane, with the base line of the tooth extending in the longitudinal direction of the strip. Such prior art, metal, carpet hold down strips are well exemplified by the strips illustrated and described in the complete specifications of Australian patent No. 151119, and lapsed patent application No. 1450/66.

3 It is desirable, to reduce their cost, to make hold down strips from the lightest gauge of metal compatible with their satisfactory performance. The horizontal forces imposed on the teeth by the stretched carpet are considerable, as are the vertical forces applied to them by the carpet layer when initially forcing the carpet into engagement with the teeth. Both those forces tend to bend prior known teeth about their base lines, and the need to ensure adequate stiffness against bending at the junction of each tooth and the channel web has set a lower limit to the metal thickness that may be used in prior art strips.

An object of the present invention is to provide a metal, carpet hold down strip which may be of lighter gauge metal than has been possible hitherto in prior art strips of comparable functional capacity.

The invention achieves that object by providing a strip wherein the teeth lie in substantially vertical planes and the base lines of the teeth extend transversely of the longitudinal direction of the strip.

The invention consists in a carpet hold down strip of the kind comprising an elongated body strip with a plurality of essentially planar ooo teeth projecting upwardly therefrom, characterised in that each tooth lies 20 in a substantially vertical plane and in that the base line of each tooth

SS

extends transversely of the longitudinal direction of the body strip, wherein the elongated body strip is an inverted channel comprising a web, a front flange and a rear flange and the front flange is inclined rearwardly to provide, in use, greater space ahead of the strip, between S: 25 it and a wall, to receive and retain an edge of a carpet between the strip o* and the wall.

4 Preferably each tooth is so shaped as to present an apex forward of the base line. Each tooth may, for example, be a scalene triangle.

The carpet hold down strip may be provided with pairs of stiffening ribs at regular intervals along its length and with fastener clearance apertures between the ribs of each pair thereof.

For preference, the carpet hold down strip is provided with spaced apart tear lines extending transversely of the strip and more preferably the spaced apart tear lines permit a strip to be broken in two at each line by hand.

The carpet hold down strip may further comprise fasteners frictionally retained in the respective apertures. The fasteners may, for example, be frictionally retained by means of grommets therein and the grommets may be in the form of plastics or rubber grommets.

By way of example, an embodiment of the above described invention is described in more detail hereinafter with reference to the accompanying drawings.

•Figure 1 is a perspective view of a length of carpet hold down strip in accordance with the invention.

Figure 2 is a plan view of the length of strip of figure 1.

20 Figure 3 is a side elevation of the length of strip of figure 1.

*oL So 0•o 0 Figure 4 is a sectional view taken on line 4-4 of figure 2, drawn to a larger sc3le.

Figure 5 is a sectional view taken on line 5-5 of figure 2, drawn to a larger scale.

The elongated body strip of the illustrated hold down strip is an inverted channel of light gauge, preferably galvanised, steel sheet comprising a web 6, a front flange 7 and a rear flange 8.

The channel may be formed from a flat steel strip by passing the strip in step-by-step manner through one or more dies which press pairs of stiffening ribs 9 into the strip at regular intervals, punch fastener clearance apertures 10 between the ribs 9 of each pair thereof, form spigots 11 on the underside of the strip rimming each aperture punch a plurality of triangular teeth 12 from the material of the strip to leave a corresponding plurality of triangular holes 13 therein, form a plurality of spaced apart tear lines (not shown) extending transversely of the strip and form the strip into a channel.

The said tear lines may be deep scores extending transversely of the strip from edge to edge. Alternatively the tear lines may comprise such scores extending across the web of the finished strip in alignment with slits through the flanges of the strip. Yet again each tear line may be a row of closely spaced perforations extending transversely of the strip. Whatever form they may take, the tear lines permit a strip to be broken in two at each line by hand. Thus strips according to preferred embodiments of the invention may be manufactured in long lengths, which may be readily reduced in length to suit particular on site requirements.

6 It will be noticed that each tooth 12 is a scalene triangle with its apex well forward of its base line. This provides the effective inclination of the tooth notwithstanding that the tooth as a whole lies in a substantially vertical plane. It will also be seen that the base line of each tooth extends transversely of the strip. It follows that for the tooth to fail under the tension load of the carpet it would have to be torn from the web 6, This requires a much greater force than that required merely to bend over prior art teeth.

In this embodiment the front flange 7 is inclined rearwardly. In use, this provides greater space ahead of the strip, between it and a wall, to receive and retain an edge of a carpet between the strip and the wall.

'040 In preferred embodiments the strip may be marketed with 0 :a0appropriate fasteners, for example masonry nails, frictionally retained in 15 the respective apertures 10, either directly or by means of rubber or plastics grommets therein.

*•04In preferred examples in general accordance with the illustrated embodiment, fastener apertures 10 may be provided at intervals of say 0 from 100 to 200 mm, preferably about 135 mm, along the strip, with 20 correspondingly spaced tear lines, preferably midway between neighbouring apertures.

4 It will be appreciated that modifications to the invention can be readily made without departing from the scope of the inventive concept.

For example, the inclined edges of the tooth illustrated may be curved or arcuate rather than straight and the tooth may include a plurality of apices.

Claims

1. A carpet hold down strip comprising an elongated body strip with a plurality of essentially planar teeth projecting upwardly therefrom, characterised in that each tooth lies in a substantially vertical plane and in that the base line of each tooth extends transversely of the longitudinal direction of the body strip wherein the elongated body strip is an inverted channel comprising a web, a front flange and a rear flange and the front flange is inclined rearwardly to provide, in use, greater space ahead of the strip, between it and a wall, to receive and retain an edge of a carpet between the strip and the wall.

2. A carpet hold down strip according to claim 1 wherein each tooth is so shaped as to present an apex forward of the base line.

3. A carpet hold down strip according to claim 2 wherein the tooth is a scalene triangle.

4. A carpet hold down strip according to any one of the preceding claims wherein the strip is provided with pairs of stiffening o ribs at regular intervals along its length. S. S

5. A carpet hold down strip according to claim 4 wherein the stiffening ribs extend transversely of the strip. 20

6. A carpet hold down strip according to any one of t claims 4 or 5 wherein the strip is provided with fastener clearance apertures between the ribs of each pair thereof. S S*i So o goS .e.5 S So

7. A carpet hold down strip according to claim 6 wherein the strip is provided with spigots on the underside of the strip rimming each aperture.

8. A carpet hold down strip according to any one of the preceding claims wherein the strip is provided with spaced apart tear lines extending transversely of the strip adapted to permit the strip to be broken in two at each line by hand.

9. A carpet hold down strip according to any one of the preceding claims further comprising fasteners frictionally retained in the respective apertures.

A carpet hold down strip according to claim 9 wherein the fasteners are frictionally retained in the respective apertures by means of grommets therein.

11. A carpet hold down strip according to any one of the preceding claims wherein the strip is formed of light gauge steel sheet and wherein each tooth is punched from the material of the strip to leave a corresponding triangular hole therein.

12. A carpet hold down strip substantially as hereinbefore "described with reference to the accompanying drawings. Applicant JOHN LYSAGHT (AUSTRALIA) LIMITED o t Date 2 February 1994 0 Attorney ROBERT G. SHELSTON F.I.P.A.A. of CARTER SMITH BEADLE coco ABSTRACT A carpet hold down strip adapted to be fixed to the floor of a room to be carpeted adjacent to its walls, and adapted to engage the margin of the carpet to enable the carpet to be stretched across the floor area and ensure that it remains so comprising an elongated body strip of inverted channel section with a plurality of essentially planar teeth (12) punched from the web of the channel projecting upwardly therefrom, characterised in that each tooth (12) lies in a substantially vertical plane and in that the base line of each tooth extends transversely of the longitudinal direction of the body strip. In use, the strip rests upon the 10 edges of the channel flanges and may be secured to the floor by fasteners extending through clearance holes (10) in the web Each So tooth (12) of the metal hold down strip has been shaped as a scalene triangle extending substantially vertically upwardly from the base line of the triangle (along which the tooth is united to the channel web to the apex of the triangle (constituting the pointed end of the tooth) which is well forward of the base line. That is to say, each tooth is a triangle of sheet metal lying in a vertical plane, with the base line of the tooth exitending transversely to the longitudinal direction of the strip. In use, 0•0~ the strip is set so that the points of the teeth are directed towards the 20 wall. Thus, a carpet may be placed with an edge against a wall and a margin overlying a hold down strip adjacent to the wall. If the carpet is then stretched away from the wall, the teeth bite into it to prevent its edge from moving away from the wall, and, due to their shape, that is the inclination of their inclined edges, simultaneously draw the carpet down onto the strip.