CA2714807A1 - Furniture leg floor protector - Google Patents

Abstract

To facilitate installation of a furniture leg floor protector, while providing secure attachment of the floor protector to the furniture leg, embodiments of the present invention employ shrinkable tubing, for example heat-shrink tubing, to secure the floor protector to the leg.
Such a floor protector may comprise a tube of drinkable material that can be shrunk by application of heat or other suitable means, the tube having at normal temperatures a predetermined unshrunk cross-sectional size large enough to permit the tube to receive the foot portion and a shrinkage rate sufficient for the tube to be shrunk to a cross-sectional size that is smaller than the foot portion so that, when the tube is placed over the foot portion and shrunk by application of heat or other suitable means, as aforesaid, the tube will conform to and adhere to the underlying foot portion and secure the floor protector to the foot portion.

Description

FURNITURE LEG FLOOR PROTECTOR
DESCRIPTION
RELATED APPLICATIONS

[0001] This application is related to United States Patent Serial Application No.
12/082,054 filed April 8, 2008, the entire contents of which are incorporated herein by reference.
This application is also related to United States Provisional patent application number (Attorney docket number AP 1537USP) the contents of which are incorporated herein by reference.

FIELD OF THE INVENTION

[0002] This invention relates to furniture leg floor protectors, and, more particularly, floor protectors for use with legs of chairs, tables, stools, sofas, room dividers, or any other furniture having legs (hence feet) to protect the floor when the furniture is moved, whether by sliding or rocking.

BACKGROUND OF THE INVENTION

[0003] Furniture leg floor protectors have been in use for many years to avoid damage to the floor when a piece of furniture is moved, They also reduce noise in the classroom where children move their desks and chairs around often making an irritating noise.

(0004] Some known floor protectors for furniture legs comprise a disk of synthetic plastics material, or metal, which can be fixed to the end of the leg by adhesive or a screw.
Attached to the underside of the disk is a pad of felt or other suitable protective material which contacts the floor. For example, US 2005/0003723 (Brouard et al.) discloses floor protectors for fastening to the underside of the foot of the leg by adhesive or by a hook-and-loop fastener (e.g., Velcro), so that it can be replaced more easily. US 2008/0148522 (Beshore), as another example, discloses a three-part floor protector which comprises an inverted cup for securing by its base to the furniture leg by means of a screw. Engaged in the inverted cup are a glide of non-abrasive synthetic plastics material, an interposed resilient washer. US
2007/0234507 (Vorpahl) 1 <

discloses yet another example in the form of a glide assembly which has interchangeable hard and soft bases and several attachment devices which can be adapted to the foot of the furniture leg and the type of floor.

[0005) Sometimes, it is not practical or desirable to fasten the floor protector using a screw fastener or adhesive, For metal or plastics furniture legs having an enlarged foot portion, perhaps in the form of a disk or toroid, or even an adjustable foot or glide fastened by a screw, it is known to use a slip-on floor protector in the form of a unitary boot of rubber or synthetic plastics material which fits over the foot/glide and grips its upper surface, The boot may itself contact the floor or may carry a pad of felt or other protection material.
Examples of slip-on floor protectors are disclosed in US 2,865,133 (Hoven et al.), US 6,405,982 (Ferencz), and US

6,754,934 (Shifller).

[0006] It is also known to use a slip-on floor protector which is generally in the form of a ball with a slit in the top, as disclosed, for example, in US 2007/0220703 (LaPointe et al.). The end of the furniture leg is inserted into the ball so that its foot rests on the interior of the bottom of the ball and the sides of the slit grip the furniture leg.

[0007] Because these slip-on floor protectors are relatively short, they may become dislodged relatively easily, especially when used in schools where chairs may be rocked as well as dragged. Also, the boot or ball may be considered to be unsightly.

[0008] It is known to use a floor protector having not only a boot portion to fit around the foot of the leg but also an integral tube which will extend upwards along the leg and grip the surface of the leg above the foot. US 2008/0179471 (Verdelli), for example, discloses a tube which is secured to the furniture leg by means of elastic bands or by ribbon or string tied around it. US 2008/0209686 (Lang) also discloses a floor protector secured to the foot or leg by a tie.
In one embodiment, the protector has a tube closed at one end (which contacts the floor) and a tie wrapped around portions the tube near its other end to fasten it tightly to the leg. In an alternative embodiment, the tie passes through upstanding flanges of a boot to draw them closed over the upper surface of the foot, The use of ties may not be acceptable because they may come undone and may be unsightly.

[0009] Some floor protectors rely, at least primarily, upon elasticity of the sleeve to grip the leg of the furniture, For example, US 7,124,986 (Bailey) discloses a floor protector comprising an elastomeric sleeve with one end closed, at least partially, to form a bottom to which is glued or stitched a pad of felt or other protective material. The sleeve can be stretched to fit onto the furniture leg, US 2004/0123421 (Bushey) discloses a floor protector comprising a hemispherical base and a sleeve for fitting around the furniture leg. The sleeve has resilient projections in the form of splines, flutes or leaves, which extend radially inwardly to grip the leg.
These projections may complicate manufacture yet not provide adequate grip, especially when the protector has been in use a long time and repeated flexing and aging have reduced the elasticity of the sleeve. Similarly, United States Publication No.
2004/0123421 discloses a floor protector with a corrugated sleeve having folds therein to increase friction.
it would appear, however, that the complexity of the molding process could make this option uneconomical.

[0010] United States published patent application No. 2005/0115022 (Desmarais -present inventor) discloses a floor protector having a sleeve with internal splines to grip the leg.
The problem of stretching and enlargement of the sleeve, causing it to loosen was addressed by means of a flexible coupling between upper and lower portions of the sleeve, allowing the leg to tilt while the pad beneath the foot of the leg remained flat upon the floor.
Nevertheless, this approach too is not entirely satisfactory because it entails a rather complicated, hence costly, moulding configuration.

[0011] The trade-off between ease of installation of a floor protector having an clastomeric sleeve and the security of the grip between the sleeve and the furniture leg, especially after the furniture has been dragged or tilted repeatedly during normal usage, was addressed in the present inventor's United States published patent application No. 2008/0258023, which discloses a floor protector having a sleeve which is more elastic at the top than at the bottom. This upper portion can be stretched enough to allow it to be rolled outwards, the leg/foot inserted into the less elastic lower portion, and the upper portion unrolled onto the leg.
Rolling up the stretchable upper sleeve portion facilitates installation, while the stiffer lower sleeve portion firmly grips the lower portion of the leg and provides good stability of the floor-engaging pad. Nevertheless, this arrangement may not be entirely satisfactory if fitted to heavy furniture or, in the case of an occupied chair, ti1it l and/or dragged, subjecting the sleeve to excessive stress, [0013] An object of the present invention is to overcome or at least mitigate the above-described deficiencies of such known floor protectors, or at least provide an alternative furniture leg floor protector which combines case of installation with security once it has been installed.
To this end, ombbodiments of the present invention eutploy shrinkable tubing, fbr example, beat-shrink tubing, to secure the floor protector directly or indirectly to the leg.

[0014] In this specificaon, the team "unshrunk" tube/tubing will be used M
describe the, uuudition of the tube/tubing before it has been. shrunk, and the word "shrunken" will be used to describe the tube/tubing after it has been shrunk. This does not preclydie, however. the tubeJtubing having been shrunk partially down to the 'uagn mk" size.

[0015] According to one aspect of the present invantiop, there is provided a floor protector adapted for use with funiture having at least one leg with a foot portion, the floor protector comprising a tube of shrinkable material that can be slttunk by application of hest, or other suitable means, the tube having at normal tcrnperaturec a predetermined unshrok MSS.
wtional size large enough to permit the tube to receive said foot portion and a shrinkage rate sufficient for the tube to be sluunkai to a cross-sectional size that is smaller than the fbot portion so that, when the tube is placed over the foot portion and shrunken by application of a said heat or other means, the tube will conform and adhere to the underlying toot portions and secure and seams the floor protector to the foot portion.

[0016] According to another aspect of the present invention, there is provided a method of installing a floor pmtector onto a fuut portion of a furniture leg, comprising the steps of fitting over the foot portion a tube of shrinkable material having a predetermined unshrunk cross-sectional size large enough to receive the foot portion, the shrinkable material having a shrinkage ratio sufficicnt for the tube to be shrunken to a size smaller that a =8s-sectional size of the foot portion, and shrinking the tube by application of heat or by other suitable means to cause the tube to shrink at least until the tube has conformed to the underlying surface of the foot portion to Such an extent as to secure to floor protector to said foot portion.

[0017] Preferably, the shrinkable tube is made of heat shrink material, i.e. a thamnplustic material whicb shorties when heated. it is known to use heat-shrink tubing in the dectrieal industry around connections betweou electrical conductors and between electrical conductors and terminals, to provide insulation, abrasion resistance and environmental protection. Suitable heat-shrink materials may shrink to as little as one third or one quarter of their original size and may shritdc at temperatures which can be obtained using a heat source that is relatively readily available, such as a small butane torch, an elect tttsad hot air hest gun, a paint-stipper or a hair dryer. Gcuerally, commercial hand-held hair driers would be prefwcd because domestic hair dryers operate at lower air temperatures than cormucrcial hair driers, which limits their use with heat shrink materials that are commercially available at this time. Nevertheless, use of a domestic hair dryer or other heat source is not precluded if it can provide the required .
How of air at a sufficiently high temperature 1001$) In embodiments of either aspect otthe invention, at least part of the interior of the tube may be provided with an adhesive so that, once the tube has bt n fully shrunk, the adhesive bonds the tube to the foot portion and provides additional security against the fluor protector being dislodged, Where the nthe wmpriscs heat-shrink material, the adhesive may be heat-sensitive (hot-melt) adhesive arranged to melt at a temperature similar to that required to shrink the tube. the hot melt adhesive being melted (activated) centeimpurancously with the shrinking of the tube, i.e., using the same heat source.

(0019] Preferably, the shrinkable tube is installed onto a toot portion having a non-urrifiun profile, Le., having lateral protrusions, so that, once the tube has been shrunk, the tube conforms at least partially to the protrusions and provides mechanical resistance to movement in the direction of the tubular axis tat remove the floor protector.

(00201 In preferred embodiments of either aspect of the invention the unabrunken the is partially or completely closed at one end which carries a pad of protective material, the unshnrnken tuba being greater in cross-sectional size than the foot portion of the furniture leg and having a length predetermined such that when the tube has been shrunken onto the furniture leg foot portion, a desired friudoual force between the tube and the leg or foot portion is sufficient to bold the tube and pad onm the foot portion, (0021] Preferably, the pad is embedded partially into the material of the closed end of the tube, the material of the tube infusing interstices at an upper (in use) surface of the pad. Such embedding of the pad may be attained by moldipg the tube onto the pad during moulding of the floor protector. In preferred embodiments, at least the uppermost (in use) portion of the pad comprises fibrous material, e.g. wool felt.

[0022] Preferably the shrinkable tube material is selected, both in terms of its shrinkage characteristics and dimensions, so that the shrunken tube may conform closely (tightl)'?) to the exterior of the leg and/or foot portion both to provide a desired gripping force and to avoid, at least to some extent, an unsightly result. It may be transparent so as to be less noticeable.
Suitable shrinkable materials include polyurethane, polyolefln, polyolefin, fluoropolymer (such as FEP, PTFE or Kyaaim), PVC, neoprene, silicone elastomer or Viton .

(0023] Further features and advantages of floor protectors embodying the present invention will be set out in the following description of preferred embodiments of the invention, taken in conjunction with the accompanying drawings, which descriptions provided by way of example only.

BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings:

[0024] Figures 1 A, I B, 1 C and I D are partial perspective views illustrating installation of a floor protector onto the bi-conical foot portion of a furniture leg, the floor protector comprising a shrinkable tube having at one end a protective pad; and [0025] Figures 2A, 2B, 2C and 21) are partial perspective views corresponding to Figures IA, 1B, IC and ID, respectively, but illustrating installation of such a floor protector onto a stright-sided foot portion of a furniture leg.

DETAILED DESCRIPTION PREFERRED EMBODIMENTS

[0026] Installation of a shrinkable floor protector onto the foot portion of a furniture leg will now be described with reference to Figures 1A, 113, IC and 1 D. Figure IA
shows a lowermost part of a furniture leg 100 that tapers downwards to end in a bi-conical foot portion 101 formed by an upper truncated conical section 101A which, as shown, will be upright use, and a lower truncated conical section 101B which is shown inverted, as in use.
The conical sections are joined at their respective maximum diameter bases. A generally part-spherical intermediate portion 102 connects the upper conical section 101A to the tapered leg above it.
The truncated end of the lower conical section 101E normally rests upon the floor (not shown) and if not protected, may leave marks.
[0027] Figure 1B shows a cup-shaped floor protector 103 placed beneath the lower conical section 101E of foot portion 101. The floor protector 103 comprises a cylindrical tube 104 of heat-shrink material having a pad 105 of protective material, for example wool felt, at one end. The pad 105 is shown closing the end of the tube 104 but it is not essential that it do so completely, providing it is securely attached to the end of tube 105, Before shrinking, the diameter of unshrunk heat-shrink tube 104 is greater than the maximum diameter of the conical sections 101A/101B which are received in the tube 105. The length of the heat-shrink tube 104 is significantly greater than the height of the lower conical section 101E so that the application of sufficient heat to the uppermost part of the heat-shrink tube 104 causes the uppermost part to shrink until it securely grips the inclined surface of upper conical section 101A,, as shown in Figure 1C.
[0028] In this case, the difference in diameter between the maximum and minimum diameters of the lower conical section 10113, and the diameter of the pad 105, mean that it is not practical for the shrunken heat shrink tubing 105 to conform to more than a small part of the surface of the lower conical section 101B. Nevertheless, appropriate heating of the lowermost part of tube 104 causes it to reduce in diameter and securely grip the pad 105 and the upper part of the surface of lower conical section 101 B to provide a degree of stability to the protection pad 105 without damaging the joint between the pad 105 and the and of tube 104, (0029] The grip between the heat-shrink tube 104 and the foot portion 101 may be eabanced by applying adhesive, preferably to the interior surface of tube 104 before installation, conveniently during manufacture, [0030] An advantage of using heat shrink material for tube 104 is that, as it shrinks, it will generally conform itself to the shape of the foot portion onto which it is being fitted, and grip the surface of the foot portion with significant friction. Consequently, it is envisaged that the same floor protector 103 may be fitted upon legs or foot portions having uniform surfaces and non-circular cross-sectional shapes. Thus, by way of example, Figures 2A, 2B, 2C and 2D
are views corresponding to Figures 1 A, I B, I C and I D but of the same floor protector 103 being installed onto the foot portion 201 of a square-section furniture leg 200 which has straight parallel sides. The floor protector 103 is similar to that of Figures 1A - I D
and, when shrunken onto the foot portion of leg 200 as shown in Figure 2D, relies upon friction between the tube 104 and the underlying surface of foot portion 200 to hold the pad 105 securely onto the end of leg 200 and prevent it from dislodging in normal use of the object/furniture. In this case, it may be especially desirable to provide adhesive on the interior surface of tube 104, as described above with respect to tube 104 shown in Figures lB-ID. The adhesive may be a heat-sensitive (hot-melt) adhesive preferably with a melting temperature similar to that used to shrink the tube 104 so that the activation of the adhesive will take place while the tube 104 is being shrunk onto the foot portion 101, i.e., using the same heat source, [0031] In each of the foregoing embodiments of the invention, the material of the pad 105 may be chosen according to the particular situation in which the object/furniture will be used. For example, wool felt may be preferred where the furniture is likely to be used on hardwood flooring, or where noise may be a problem, as in schools. Wool felt or other fibrous material also may be preferred for its ability to allow adhesive to penetrate into the interstices between fibers and improve adhesion and strength. The radial end surface of tube 104 and/or the end portion of tube 104 (if it extends around the pad 105) may be provided with, indentations, perforations or other formations to improve adhesion of the pad 105.
[0032] Preferably, the upper (in use) surface of the pad 105 has interstices into which the hot thermoplastic material (forming the end of tube 104) can flow during moulding, the pad 105 being used like a mould insert, (It has been found that 100% wool felt is suitable when the thermoplastic material is PVC or polyolefin). Once the thermoplastic material cools and sets the pad 105 remains permanently embedded, partially, in the end of tube 104. It should be noted that, when such partial embedding is used, the end of the tube need not be completely closed.
An annular end surface can provide sufficient area to embed and attach the pad 105 securely.
[00341 Heat-shrink materials presently readily available may be shrunk using hot air supplied by, for example, small butane torch, a heat gun, an electric hot air paint stripper, a commercial (high temperature) hair drier, or other suitable heat source, Use of a domestic hair dryer or other heat source is not precluded if it can provide the required flow of air at a sufficiently high temperature. The choice of heat source will depend upon the characteristics of the heat shrink material and the sizes of the floor protector and furniture leg foot portion. Heat-shrink tubing is available in a variety of sizes and chemical compositions, with different heat requirements. Some examples are: polyolefin, fluoropolymer (such as FEP, PTFE
or Kynar), PVC, neoprene, silicone elastomer and VitonTm.

[0035] A specific example of such a floor protector would be a 2" diameter by 2" length cylindrical shaped sleeve composed of shrinkable clear PVC with a shrink ratio 2:1 easily conforming to square funiture leg of 1-1/4" width. In this case an adhesive used inside the floor protector would have a composition resistant to plasticizers, based on polyamides in order to glue the PVC. The felt pad at the bottom could be 1/4" thick by 2" in diameter or less if we want the felt to match the shrunken size rather than the unshrunken size.

[0036] It should be appreciated that heat-shrink material used for insulating electrical conductor splices and terminations is tubular and formed by extrusion, which requires lower temperatures (e.g. about 80 C) than injection moulding temperatures (e.g. 100-150 C) because the extruded tube must be firm enough to pull while the injected plastics material must be viscous enough to flow. However it is possible to injection mold PVC and polyolefin using a lower injection temperature and higher injection pressure, especially with simple shapes such as a small cylindrical shape (as in embodiments of the invention) where the molten material has a simple path to follow in order to fill the mold.
[0037] An advantage of floor protectors embodying the present invention is that they do not rely primarily upon elasticity of the heat-shrink material of tube 104 being sufficient for it to be stretched during installation and then grip the furniture leg elastically to retain the floor protector in place; rather, embodiments of this invention rely upon the unsbrunk heat-shrink material tube 104 being sized to fit easily onto the foot portion, which allows easy installation, and being capable of being shrunk to such an extent that it conforms closely to the underlying surface of the furniture leg foot portion, whereupon inherent tackiness or striation of the heat-shrink material provides good frictional engagement. The security of the installation is further improved where the contour or profile of the underlying leg surface is not straight, so conformance of the shrunken tube to the foot portion provides additional mechanical locking, particularly since the more the heat-shrink material is shrunk, the more inelastic it becomes; and yet further improved by using an adhesive.
[0038] It is envisaged that the shrinkable tube 104 could be shrunk onto both pad 105 and foot portion 101, in which case the pad 105 might be stepped so that a central portion protrudes beyond the end of the tube to contact the floor when the floor protection is in use.
[0039] It is preferred, however, to mould the floor protector 104 as a single unitary component, similar to heat-shrink and caps for insulation electrical conductor ends, but with the pad 105 embedded in the heat-shrink material during moulding.
[0040] There is a trade-off between the thickness and shrinkage ratio of the heat-shrink material, which thickens as it shrinks. A shrinkage ratio of 2:1 is preferred so that the final thickness of tube 104 is not too great. Nevertheless, a shrinkage ratio of 3:1 of 4:1 might allow a single size of floor protector to be used with a wider range of sizes of foot portion 101 and would likely be clearer (when transparent),

Claims (14)

1. A floor protector adapted for use with furniture having at least one leg with a foot portion, the floor protector comprising:

a tube of shrinkable material that can be shrunk by application of heat or other suitable means;

the tube having at normal temperatures a predetermined unshrunk cross-sectional size large enough to permit the tube to receive said foot portion and a shrinkage rate sufficient for the tube to be shrunken to a cross-sectional size that is smaller than the foot portion so that, when the tube is placed over the foot portion and shrunk by application of heat or other suitable means, the tube will conform to and adhere to the underlying foot portion and secure the floor protector to the foot portion.

2. A floor protector according to claim 1, wherein the tube is partially or completely closed at one end and said end carries a partially-embedded pad of protective material having interstices, the unshrunk tube having a length predetermined to provide, when shrunk onto the furniture leg, a frictional force between the tube and the foot portion sufficient to hold the pad onto the foot portion, the material of the end portion of the tube penetrating into said interstices to secure the pad permanently to the tube.

3. A floor protector according to claim 1 or 2, wherein the shrinkable material has a shrinkage ratio of about 2:1.

4. A floor protector according to claim 1, 2 or 3, wherein the pad comprises at least one of polyester, wool, nylon, rayon, Teflon(.TM.), and cotton,

5. A floor protector according to claim 1, 2, 3 or 4, wherein said pad comprises a mixture of any two of the group consisting of polyester, wool, nylon, rayon, Teflon(.TM.) and cotton.

6. A floor protector according to claim 1, 2, 3, 4 or 5, wherein the felt comprises wool felt.

7. A floor protector according to any one of claims 1 to 6, wherein said pad is circular with planar top and bottom surfaces.

8. A floor protector as claimed in any one of claims 1 to 7, wherein said pad includes a central aperture.

9. A floor protector according to any one of claims 1 to 8, wherein the end of the tube to which the pad is attached has a central aperture.

10. A floor protector according to any one of claims 1 to 9, wherein at least part of the interior of the unshrunk tube is provided with a heat sensitive (hot-melt) adhesive arranged to melt at temperatures such that the adhesive will be melted contemporaneously with the shrinking of the tube and, once the tube has been shrunk onto the foot portion, the adhesive will bond the tube to said end foot portion.

11. A floor protector according to any one of claims 1 to 10, wherein the shrinkable material comprises a heat-shrinkable thermoplastic material selected from a group including polyoleful,

12 fluoropolymer (such as FEP, PTFE or Kynar (.TM.')), PVC, neoprene, silicone elastomer and Viton (.TM.).

12. A floor protector according to claim any one of claims 1 to 11, wherein the shrinkable material has a shrinkage ratio of at least 3:1.

13. A method of installing a floor protector onto a foot portion of a furniture leg, comprising the steps of:

fitting over the foot portion a tube of shrinkable material having a predetermined unshrunk cross-sectional size large enough to receive the foot portion, the shrinkable material having a shrinkage ratio sufficient for the tube to be shrunk to less than a cross-sectional size of the foot portion; and shrinking the tube by application of heat or by other suitable means to cause the tube to shrink at least until the tube has conformed to the underlying surface of the foot portion to such an extent as to secure the floor protector to said leg.

14. A method according to claim 13, for installing a floor protector having the features of any one of claims 2 to 12.