SILICONE-COATED FURNITURE

FIELD OF THE INVENTION

The invention relates to laminated furniture and more particularly to furniture for us 2 in high-traffic areas, such as institutional or health care settings.

BACKGROUND OF THE INVENTION

Silicones are a family of inorganic polymers which feature a silicon-oxygen backbone with side groups attached to the silicon atoms. Silicones, while generally flexible -and translucent, can be formulated to have different densities and textures. Silicones may be in liquid, gel or solid form. Silicones have been used successfully in many consu ner and industrial products, from baby bottle nipples to flexible bake wear to surc ical implants to food additives and industrial adhesives.

SUMMARY OF THE INVENTION

Silicone has not, to the applicant's knowledge, previously been used as a furni ture laminate. In an elastomer form, silicone has a lovely soft feel which would make a comfortable surface for sitting on or resting against.

It is an aspect of the invention to provide a method of laminating a furniture item for high- traffic use. A layer of silicone elastomer is applied to the furniture item in cured or liquid state to sealingly cover at least the surfaces of the furniture item exposed to hu man contact. Then, if uncured, the silicone elastomer is allowed to cure. Preferably, the silicone elastomer has a cured Shore hardness of at least about 10. Preferably, the silicone elastomer has a minimum finished thickness of about 1 mm.

The terms "laminate" and "laminating" are used herein to mean that the silic one elastomer acts as a separate layer disposed on the furniture item. The silic one elastomer layer and the furniture item may be joined together chemically, mechanic ally or by some other factor. It is not intended that the invention be limited to any particular type of bond or engagement between the surface of the furniture item and the silicone elastomer. Likewise, the term "sealingly" is intended to mean only that the surface ilself is sealed (i.e. generally impervious), not that the laminate is joined to the furniture item in any specific sealing engagement.

In one embodiment of the method, overmolding is used to apply the silicone elastomer to at least one portion of the furniture item. The silicone elastomer is then allowed to cure.

In another embodiment of the method, a measured amount of silicone elastome r is compression molded and pre-cured as a sheet. That sheet is then applied to at h-ast one portion of the furniture item; and then mechanically or chemically secured to the furniture item. For instance, the "sheet" of silicone elastomer may be molded like a bag or envelope, which is then draped or wrapped or otherwise positioned on the furniture item. To give another example, the silicone elastomer may be formed like a shower cap, which is then fitted over the seat pan (or back, or some combination). The loose edges of the cap (or sheet) may be simply left loose, or they may be tucked in to some corresponding part of the furniture item (preferably, away from the human contact surfaces), or they may be secured by one or more secondary pieces of hardware (such as fastening devices, or plates, or other reinforcements). Most standard adhesives will not readily bond to silicone. However, it is contemplated that some chemical forn of bonding may also be used for the securing.

In a still further embodiment of the method, a pre-cured silicone elastomer sheet may be cut or shaped to a particular size or shape; wrapped around at least one portion of the furniture item; and mechanically or chemically secured to the furniture item.

A wide range of possible formulations may be used for the silicone elastomer in the method to obtain suitable results as a furniture laminate. Preferably, the cured silicone elastomer should have a soft, non-sticky feel and a matte finish. In practice, the finished appearance may be either matte or shiny, but shiny appearance may be coincident with stickiness in silicones, and it is desirable that the silicone elastomer should not be stcky to the touch. The silicone elastomer may be translucent or opaque. It may be colored or pigmented.

A laminated furniture item is also provided in accordance with the method. The furni :ure item may be any of the following: a chair, a stool, a footrest, an ottoman, a bench, a sofa, a cushion, a table, a nightstand, a desk, a bed, a backrest, or any accessor/ or part therefor.

The laminated furniture item may be for use in an institutional setting, particularly a health care setting. However, it is imagined that the laminated coating would make the laminated furniture suitable for almost any type of environment, and particularly h gh- traffic use. "Institutional" should be read here with the widest possible meaning, including (without limitation): public seating/waiting areas (such as in hospitals, clinics, bus/train depots, shopping malls, offices, airports, schools, arenas) and areas where any type of physical treatment, therapy, examination or exercise is usually carried out (s uch as gyms, sports facilities, medical, dental or other clinical facilities, laboratories, spas,

aesthetic treatment facilities, rehabilitation/treatment facilities, child care facilities, weight loss centers).

Furniture produced or treated according to the method may be made in various shapes, sizes and configurations. Considering the possible insititutional uses of the furniture, it may be desirable to manufacture such items in bariatric sizes (for use with very large or obese people).

Apart from the method, it is another aspect of the invention to provide a laminated furniture item for high-traffic use. A furniture item body has a layer of silicone elastomer sealingly covering at least the surfaces exposed to human contact. The silicone elastomer preferably has a cured Shore hardness of at least 10, and a thickness of at least about 1 mm. The furniture item preferably has a contact surface comprising air flow perforations. The silicone elastomer layer extends through without filling the perforations. This perforated contact surface may be any surface of the furniture ilem. For instance, the contact surface may be a seat pan, a back rest, or an arm rest. However, the furniture item is not limited to a chair, and these particular surfaces are not critical.

One or more surfaces of the (unlaminated) furniture item may be uneven or textured. For instance, the seat pan may have an uneven or textured surface. In one embodiment, the silicone elastomer layer of the laminated furniture item has a smooth top surface which does not visually replicate the uneven or textured surface. This nay provide a separate internal landscape that is touch-perceptible when the silicone elastomer layer is compressed. Such a surface may have many benefits (both functional and aesthetic). One such benefit may be to provide pressure relief vhile

sitting. This feature may also be provided in combination with the aforementioned perforations.

In a further aspect of the invention, a health care furniture item is provided with the foregoing features. In addition to these features, it is contemplated that the formulation and thickness of the silicone elastomer being used would be especially selected to provide a fluid-impervious coating on the furniture item, and to inhibit proliferation ;and propagation of fungi, viruses, bacteria and other communicable or infectious agents on the furniture item. The formulation and thickness may also be especially selectee! for ease of cleaning and disinfection.

A particular embodiment of the health care furniture item is a health care chair. The chair may have many variations and configurations, including (without limitation) a standalone chair, a ganged chair configuration, a legged chair, a chair on a beam, a chair on a base with wheels. The chair may have arm rests. For health care use, the arm rest may be movably connected to the chair body to permit stowing the arm rest when not in use, or to provide clear access to a patient seated in the chair.

BRIEF DESCRIPTION OF THE FIGURES FIG. 1 shows a portion of a laminated chair according to an embodiment of the present invention.

FIG. 2 shows a cut-through view of a chair seat portion showing interior construction according to one embodiment.

FIG. 3 shows a portion of a laminated chair according to a bariatric embodiment. FIG. 4 shows a laminated chair with base.

FIG. 5 shows a laminated chair with base and having optional arm rest features.

FIG. 6 shows another view of a laminated chair according to a bariatric embodiment. FIG. 7 shows a laminated stool with wheeled base. FIG. 8 shows laminated chairs in a ganged embodiment.

DETAILED DESCRIPTION

The present invention relates to laminated furniture and more particularly to fumϊ ure items laminated with silicone elastomer for use in high-traffic areas. As shown in Fie . 1 , a basic embodiment of the invention is a chair. The chair may have a unitary bach 20 and seat 30 construction as shown, or may be in separate pieces. Surfaces of the c iair that are exposed to human contact (such as the seat pan portion 30) are laminated with silicone elastomer 70 as shown in Fig. 2. The seat portion 30 has a top surface 50 nnd a bottom surface 60. The entire chair back 20 and seat 30 may be laminated with silicone elastomer, or only the top and front surfaces thereof.

While silicone application can be accomplished in many ways (including roll ng, spraying, calendaring, and other application processes), the following methods have been found particularly useful for furniture lamination in the present invention: 1. Overmolding the furniture item (or portions thereof) with silicone elastomer in a liquid form; 2. Fitting a compression molded sheet of pre-cured silicone elastomer over or onto the furniture item; or

3. Cutting or shaping a pre-cured sheet of silicone elastomer to a desired size .;ιnd shape, and fitting the sheet over or onto the furniture item.

In the first method, the furniture item is placed in a specially constructed mold and liquid silicone elastomer is injected through one or more gates to coat the item to a desired

thickness. Depending on the formulation of the silicone elastomer, curing may be at ambient temperature, or the silicone elastomer may be heat-cured or cured with a curing agent. In one possible embodiment, the silicone may be platinum cured liquid silicone. In its liquid state, the silicone elastomer flows around and into all of the surface features of the furniture item, including all holes and bosses. The finished surface of the silicone elastomer may be controlled by polishing or roughening the interior surface in the rrold. The surface can be made to have a shiny or matte finish, and various surface textures may also be produced. The silicone elastomer itself may have additives such as stiffeners, colorants (pigments), or anti-static agents to change the look, fee or performance of the finished product.

The mold itself may be specially tailored for large scale application of liquid silicone elastomer. Depending on the formulation, care may need to be taken to prevent air entrainment (bubbles). Thermal expansion may also be a concern.

The bond between the silicone elastomer and the furniture substrate may be mechanical or chemical. It may be necessary or desirable, depending on the substrate and the formulation of the silicone, to prime the surfaces of the furniture item to be overmolded. A chemical primer may be used for this purpose. There are many suitable material::; for the furniture item substrate. Some examples are metal, wood and molded pla stic. Useful plastics include graphite epoxy composite and PBT-PC.

Preferably, the finished thickness of the silicone elastomer layer for the present application will be variable. On average, the thickness may be between about 1 :o 2 mm. The layer may be made intentionally thicker in localized areas (4 mm+), sucti as around edges, for improved comfort or wear. Below about 1 mm, the laminate may be

too thin to have a protective benefit, and may tear or fray in high use. Above a certain thickness, the silicone material may make the finished item too heavy, or the item may be prohibitively expensive to manufacture.

The desired "feel" characteristics of the laminate can be controlled by using diffe ent formulations of the silicone elastomer. A silicone elastomer formulation that has a cured Shore hardness in the range of 10 to 80 provides a sufficiently soft feel for silling comfort. However, higher durometer ranges are possible without a loss of functions; lity. In certain formulations and surface finishes, it may be necessary to have ano :her material as an overlay to prevent sticking, although recognizing that this may defeat the hygienic benefit and clean look of the exposed silicone, which are desirable for the present invention.

The second method for applying silicone elastomer uses a compression molded (pre- cured) sheet (or bag) of silicone elastomer that is draped or enveloped over the furni :ure item (or surface) to be coated. To retain the sheet on the furniture item, a reinforcement plate (not shown) or other hardware may be used to secure the edges (for example on the back surface of the back support or on the underside of the seat pan). In :>ne possible embodiment, the compression molded silicone is a peroxide cured high consistency silicone rubber.

This second method may be particularly useful for larger items, which may be difficu ^l t or impossible to overmold (or cost-prohibitive). Larger-scale chairs (such as those for bariatric users), tables, beds, etc. may be laminated using this second method.

A third method is also possible, which uses cut or shaped sheets of silicone elastomer. This may be particular useful to cover large, flat surfaces. Additional hardware may be used to attach the sheets to the furniture item, or the sheets may be chemically bonded.

Turning to Fig. 2, the silicone elastomer may be in conjunction with a textured or irregularly surfaced substrate 80. For instance, the textured substrate may have a dimpled or ridged surface. The applicant has also found that a useful seating structure can be provided by combining two different densities of silicone. Over a hard pl<: stic shell 90, an irregular layer of silicone foam may be provided, and silicone elastomer 70 provided over and/or around the irregular foam surface. Preferably, the top surface £:0 is visually smooth and flat betraying no surface irregularity. When the silicone elastomer is compressed (such as by sitting on the seat), preferably the irregular surface will be perceived by feel. According to one possible configuration, the interior landscape of the seat may be textured to have the feel (without the look) of a dimpled or beaded surf -ice. The raised lands or dimples may be particularly designed to optimize comfort and pressure relief, so as to prevent decubitis sores. It will be appreciated that the textured foam interlayer may be replaced with another material or eliminated altogether. The plastic shell itself may have a textured surface.

As shown in Figs. 1-3, the seat portion 30 and/or the back portion 20 may be provi ded with throughholes (perforations) 40 for air flow (breathability) and moisture egress. The holes extend through the seat portion and/or back portion and are preferably coatee on the inside with the silicone elastomer laminate. Any shape and configuration of holes may be provided. (Buildup of moisture may be a particular concern in health care und institutional settings, where patients may be bleeding or experiencing other fluid loss.) Silicone is moisture impervious.

Preferably, as shown in Fig. 4, the chair 10 may be assembled in a standard stacking chair format, having a standard base with legs 100. The base may or may not be coated with the silicone elastomer.

Arm rests 110 may be provided as shown in Figs. 4 and 6 (laminated or not). Arm rests may be provided with an optional swing-away design as shown in Fig. 5. In this variant, the arm rest 110' may be rotated or swiveled at joint 120 to clear or stow it away from the central sitting region of the chair (down, back or to the side). In an institutional or health care setting, this feature may be particularly useful for patient access.

Many size and configuration variations of the laminated chair are possible. The chair may be provided in a "bariatric" size 10' (to accommodate very large or obese people), as shown in Fig. 3 and 6. Backless chairs and stools may be provided, such as the stool configuration 140 shown in Fig. 7. The stool top 150 may be the laminated portior , or the entire stool, including base 130, may be laminated. Chairs may also be provided in standalone or ganged 160 variations on a beam base 170 (such as shown in Fig. 8/. It will be appreciated that the process is also not limited to chairs and other "seating" furniture (such as sofas, benches, and the like), but may also apply to other furni ture items, such as beds, tables, foot rests, cushions, etc.

In the health care and institutional context, specialty furniture may be laminated, such as examining tables, patient support furniture and equipment (crutches, walkers, car us), wheelchairs, toilet seats, potty chairs, bed rails, and others.

In a health care and institutional context, the silicone coating is particularly useful . is the silicone has naturally inert properties. It is resistant to bacteria, viruses, and fung , and water-impervious. Also, unlike fabric or mesh furniture coverings, the silicone will not fray or become worn in use. It has an easy-care surface which wipes clean with s mple soap and water, but it will also hold up against harsh cleansers and chemical washes. Where smoking is permitted, ash burns can develop on conventional furniture. Silicone is naturally resistant to high heat and will not bum from cigarette ash.

The foregoing description illustrates only certain preferred embodiments of the inver tion. The invention is not limited to the foregoing examples. That is, persons skilled in th s art will appreciate and understand that modifications and variations are, or will be, pos sible to utilize and carry out the teachings of the invention described herein. Accordingly all suitable modifications, variations and equivalents may be resorted to, and such modifications, variations and equivalents are intended to fall within the scope of the invention as described and within the scope of the claims.