FIELD OF THE INVENTION

This invention relates to a novel modular carpet tile mat or self-contained floor covering and a process of making same. More particularly, this invention relates to a novel modular carpet tile mat construction which holds carpet tiles together in a fixed position so that the assembly may be used as a mat or carpet for floor covering and floor sign purposes.

BACKGROUND OF THE INVENTION

Carpet tiles have recently become popular as a floor covering material. They offer many advantages over standard roll-type carpet floor covering. The tiles, which are approximately 0.5 meters (18 inches) square, can be laid over a floor or other area in a mosaic or grid pattern and can easily be individually removed for cleaning or replacement purposes, when individual tiles become soiled or worn. A complete or partial floor covering of carpet tiles is generally inexpensive over time because only the worn or soiled carpet tiles need be removed. The remaining unworn or unsoiled portion of the carpet may be saved and kept in place. This is unlike conventional roll carpet flooring.

Carpet tile also provides more flexibility in carpet design since tiles may be swiftly replaced with a different colour to suit a particular occasion. Reversible carpet tiles of a different colour on the reverse side are also used. Recently, it has been possible to create custom designs and signs on individual carpet tiles or a combina¬ tion of tiles further expanding their creative possibil¬ ities.

In the past, carpet tile has only been used for wall-to-wall floor covering similar to wall-to-wall carpet¬ ing. Complete wall-to-wall placement of the carpet tiles was necessary because lateral support is needed to hold the tiles adjacent one another on the floor in the grid pattern and prevent tile slippage. This support has been provided by the wall base.

Restriction of carpet tiles to wall-to-wall use has precluded the use of carpet tiles as floor mats or rugs or as self-contained floor covering. There are many situations where a full wall-to-wall carpeting is not required or desired. In hospitals, for example, because of heavy traffic of heavy rolling stock, large carpeted areas in hallways and rooms are to be avoided. Carpets increase friction and have problems such as carpet wrinkling. Certain entrance areas, though, do require mats for safety and foot cleaning purposes. Often the space to be covered by the mat is an irregular shape and cannot be satisfactor¬ ily covered with a standard size and shape mat.

Carpet tiles also have the capability of being custom made so that a unique design may be embedded into the carpeting of each tile or a combination of tiles. This feature suits itself well for uses such as personalized doormats and carpet advertising.

United States Patent No. 4,353,944, issued to H. Tarui on October 12, 1982, for an invention entitled "Shoe Scraper Mat", discloses a rubber doormat to be used for scraping outdoor dirt and soil from footwear. Tarui discloses a recessed scraper mat where the edges are higher than the interior. This non-level construction is unsuit- able for rolling stock. Tarui does not disclose any modular mat features that would enable the mat to be used in different shapes or sizes. Also his mat is not used in

combination with carpet tile as carpet floor covering. Furthermore, Tarui does not disclose an inclined edging that provides a smooth transition from the surrounding floor to the mat so that rolling stock may be safely and smoothly negotiated over the mat.

A difficulty with floor mats composed of carpet tiles is that with heavy traffic, they tend to creep. The force of a pedestrian's foot, or the rolling action of a wheeled carriage, or the like, causes the mat to gradually move along a floor. A new design of floor mat incorporat¬ ing carpet tiles is required to overcome this problem.

SUMMARY OF THE INVENTION

A modular carpet tile mat for floor covering purposes comprising: (a) a mat base; (b) a mat frame of border pieces attached to the perimeter of the mat base, the border pieces being adapted to grip at least one side of a carpet tile; and (c) carpet tiles held in place by the mat frame.

The border pieces are formed from resilient material and provide vertical and lateral support for the carpet tile by constructing a mat frame around the edges of one or more carpet tiles. The carpet tiles are removably placed in the mat frame so that soiled or worn tiles may be easily removed for cleaning and replacement. The mat frame is connected to the periphery of the mat base by a heat sensitive adhesive and is formed to have smooth inclined edges. The joint-line between the mat frame and the mat base is not continuous in any direction.

Carpet tiles are forceably inserted into the mat frame and maintained in their position by the lateral pressure exerted by the mat frame on the carpet tiles. The mat base can be formed of a woven or spun-bonded polyester

fibre, nylon fibre or polypropylene fibre material which has dimensional stability and provides traction for the base of the carpet tile overlying the mat base. If desir¬ able, the carpet tiles may be partially glued with a pressure sensitive adhesive to the mat base to aid in maintaining the carpet tiles in a fixed position. Such partial gluing should not be of a permanent nature in order that soiled or worn tiles may be removed for cleaning and replacement when needed. Gluing the tiles is not normally necessary to the invention since the lateral pressure exerted by the interior edges of the mat frame keeps the tiles fixed under ordinary conditions.

The mat frame pieces are affixed to the perimeter of the mat base so that the bottom of the mat base is generally coplanar with the bottom of the mat frame pieces. There is thus no gap between the mat frame and an underly¬ ing floor surface. Furthermore, the top surfaces of the mat frame pieces are inclined outwardly to provide a smooth inclined transition from floor to carpet.

The mat frame pieces may be of any smooth linear shape including straight, circular or curved. The edging pieces are of cooperating lengths for modular interconnec- tion purposes. The modular interconnecting feature enables mats of a variety of shapes and sizes to be formed includ¬ ing geometric shapes such as triangles, rectangles and circles and also arbitrary smooth curved shapes such as heart shapes or kidney shapes. Generally, the mat base is rectangular in shape.

A ribbed mat can be attached to the underside of the mat base and mat frame to provide for increased fric¬ tion between the modular carpet tile mat and the underlying floor surface. Instead of the ribbed underlying rubber mat, the mat base and mat frame themselves may be ribbed or roughened to increase friction with the floor surface. The

underside of the mat base can have a roughened surface formed by resilient traction material or foamed or expanded resilient plastic or rubber. The top surface of the mat base can also have similar friction material on it to enhance grip between the mat base and the overlying tile.

The inside upper edge of the mat frame may be inclined inward or have a protrusion with respect to the carpet tile so that the vertical gap between the carpet tile and the edging piece is minimized and the carpet tile is more tightly gripped. In this way, the carpet tile is less likely to be inadvertently removed from the mat frame. The inside upper edge of the mat frame may also protrude in a lip fashion over the top of the edge of the carpet tile so that the vertical gap between the carpet tile edge and the mat frame is eliminated.

The modular carpet tile mat comprises at least one mat frame means, at least one carpet tile, and at least one mat means. The carpet tile is glued to the mat means by releasable pressure sensitive adhesive. The carpet tile may either singly or in combination with other tiles include a design thereon. The mat frame and carpet tiles may be of a variety of different colours.

DRAWINGS

In drawings which illustrate specific embodiments of the modular carpet tile mat and a surface for assembling the components of the mat, but which should not be con¬ strued as limiting the scope of the invention in any way:

Figure 1 illustrates a plan view of a floor mat with mat frame and two carpet tiles surrounded by the frame;

Figure 2 illustrates a plan view of an assembly table, with grooves arranged in a grid-like pattern, used for assembling a mat base and a mat frame together;

Figure 3 illustrates an end view of a mat frame groove formed in the surface of the assembly table;

Figure 4 illustrates a bottom view of a mat base, surrounding mat frame, and corner stabilizers;

Figure 5 illustrates a section view of a mat frame component;

Figure 6 illustrates a section view of an alter- native double flange mat frame component;

Figure 7 illustrates a section view of a double flange mat frame component, with a mat base fitting in between the two flanges; and

Figure 8 illustrates a schematic section view of the components making up a mat base.

DETAILED DESCRIPTION OF A SPECIFIC EMBODIMENT OF THE INVENTION

We have invented a novel construction of floor mat, adapted to accommodate one or more carpet tiles, and a process for assembling the floor mat combination. Referring to the drawings, Figure 1 illustrates a plan view of a floor mat 2, which as seen in Figure 1 has a rectangu¬ lar shape, constructed of a rectangular frame constructed of four mat frames 6, with bevelled corners, the four assembled mat frame components 6 enclosing two square carpet tiles 8. As can be seen, the two square carpet tiles are held in adjacent position within the four compo-

nents making up the mat frame 6, to form a tight stable rectangular floor mat 2.

Figure 2 illustrates a plan view of an assembly table 10, which has formed therein in grid-pattern a series of parallel grooves 12 extending the length of the assembly table 10 and a corresponding parallel series of grooves 14 extending at right angles to grooves 12 across the width of the table 10. The assembly table 10 is used to construct and glue together the components of the floor mat 2, as will be explained later.

Figure 3 illustrates an end view of a groove 12, formed in the surface of the assembly table 10. The groove has two depths, a shallow depth and a bottom depth. The shallow depth is in the form of a shelf 16, which is at an elevation higher than the bottom of the groove 18. This configuration is adapted to accommodate the bottom surface shape of a mat frame 6 component.

Figure 4 illustrates a bottom view of a floor mat 2, constructed with a square mat base 4, enclosed by four mat frame 6 components, which form a square framing the mat base 4. The four mat frame components 6 have bevelled corners and once assembled, are glued together under pressure using a heat sensitive adhesive. The four mat frame components 6 are assisted in assembly in a square shape by being placed in the appropriate length grooves 12 and width grooves 14 of the assembly table 10. Mat base 4 is then glued by the suitable temperature sensitive adhes¬ ive to the interior sections of the mat frame 6. Four triangular shaped corner stabilizers 20 are then glued using the same adhesive at the corners of the floor mat 2. The bottom of the mat frame 6 components has a mid-ridge 22 formed in each component 6. The ridge 22 raises the interior of the frame 6 and persuades the outside edges of the frame 6 to lie flat on the floor.

The mat 4 should be constructed of a dimension- ally stable material in order to preserve the orientation of the mat frame. The mat 4 is usually constructed of a woven or spun bonded material such as polyester, polypropy¬ lene or nylon fibres. The spun bonded fibres are usually secured at the overlapping sections by a suitable adhesive. Knitted materials are not normally used because they do not have dimensional stability.

Figure 5 illustrates an end section view of a typical mat frame component 6. The mat frame 6 has formed on one side thereof, extending along the length of the mat frame 6 a lip 26 which protrudes slightly over the mat- flange 24. The bottom surface of the mat frame 6 has a mid-ridge 22 extending along the length of the mat frame 6, approximately midway between each side of the mat frame 6. The ridge 22 raises the centre of the frame 6 and persuades the external edge of the frame to lie flat on a floor. The portion of the mat frame 6 removed from the mat-flange 24 has a taper 28 which is smoothly curved so as to avoid a sharp rough corner or an edge being formed in the exterior edge of the mat frame 6, when the mat frame components are formed into a frame. This taper 28 blends the mat with the floor and enables rolling stock to be readily rolled onto the mat.

Figure 6 shows in end section view an alternative design of mat frame 6. This design has an upper mat- flange 30, formed above and parallel to the lower mat- flange 24. Otherwise, the alternative design of mat frame 6 is similar to that shown in Figure 5, namely, a lip 26 protrudes over the flange 24, and a mid-ridge 22 is formed mid-region along the length of the bottom of the mat frame 6.

Figure 7 illustrates, slightly exaggerated for illustrative purposes, an end section view of a mat frame 6, with a mat base 4 inserted between upper mat-flange 30 and lower mat-flange 24. The advantage of the upper mat- flange 30 and the lower mat-flange 24 is that they provide a holding and pinching action on the mat base 4. This forms a strong connection between the mat frame 6 and the mat base 4. The mat base 4 is typically glued on both sides between the upper mat-flange 30 and the lower mat- flange 24 by a suitable temperature sensitive adhesive to form a strong unitary unit.

Figure 8 illustrates in enlarged schematic end view the construction of a mat base 4. A preferred con- struction of mat base 4 comprises a web of woven or spun bonded polyester, nylon or polypropylene fibres 32, which are bound together by a suitable plastic binder 34. An outer resilient layer of expanded or foamed plastic or rubber 36 adheres to each side of the plastic fibres 32 and binder 34. The expanded or foamed plastic can typically be expanded polyvinyl chloride resin or rubber. The advantage of this design of floor mat 4 is that the woven or spun bonded web of polyester nylon or polypropylene fibres 32 is dimensionally stable and provides a strong wrinkle resis- tant, movement resistant reinforcing skeleton for the mat base 4. The expanded plastic 36 on both sides of the fibre 32 provides a cushion effect, and also a strong gripping action. The expanded plastic 38 on the bottom of the mat 4 provides a strong gripping action on the floor surface, and resists creep when traffic bears on the floor mat 2. The expanded plastic foam friction surface 36, on the top surface of plastic binder 34, provides a skid free anti- creep gripping action between the top surface of the mat base 4, and the overlying carpet tile 8. The combination of dimensionally stable woven or spun-bonded fibres 32 and outer foamed polymer 36 and 38 is unique.

Example

Prototypes have been made of the carpet tile mat utilizing the following components and method.

Floor Mat Components

1. Heat and pressure sensitive glue - Helmiten C2509 ^(TH a polyurethane base flexible glue;

2. Mat frame material - A thermoplastic extruded polyurethane with custom profile manufactured on a trial basis by Dow Chemical of Canada Limited;

3. Mat base fabric - Polyvinyl chloride (A/C) expanded foam over woven or spun-bonded polyester (or nylon) web (scrim) . This non-slip polyvinyl chloride foam is applied to both sides of the web (scrim) .

Method of Assembly

1. Assembly table: The product of the invention is made upside down. The right angle grid grooves in the assembly table are cut to a multiple of tile size (457.2 mm) plus a consistent gradation which amounts to about +2 mm every three tiles in both the lengthwise and widthwise directions.

2. Assembly steps: The fabric and nosing are cut to assembly table sizes. The flange, the mat frame pieces and butt face of the mat frame are cut at a 45° mitre and then glued and air dried. The mat base fabric is placed on the table. The triangular and straight fabric braces are then glued and air dried. The "skeleton" of mat frame is placed right side up adjacent to the mat base

fabric. The ends (butt faces) of the mat frame are heated with a hot air gun to about 100 ^β C to reactivate the glue and are then butted together to form a right angle corner. In a rectangle set of grooves on the assembly table, all four corners are joined to form the rectangular skeleton outline of the mat frame. The skeleton, once the glue sets, is inverted onto the mat base fabric and into the right angle grooves in the table. The flanges of the mat frame skeleton, which have glue on them, are is then heated with a hot iron to about 100 ' C to reactivate glue on flanges and bond the flange to fabric mat base. The triangle corner braces with glue are then laid on the four corners and heated to about

100 ^β C to reactivate the glue (using a hot air gun) . The finished mat is removed from the table grooves and packed for shipment. The grooves cut into the top of the assembly table ensure the production of square straight and accurate mats, which can receive and hold tile mats which are square cut to very fine tolerances of plus or minus two one-hundredths of an inch.

As will be apparent to those skilled in the art in the light of the foregoing disclosure, many alterations and modifications are possible in the practice of this invention without departing from the spirit or scope thereof. Accordingly, the scope of the invention is to be construed in accordance with the substance defined by the following claims.