This application is based on and hereby claims the benefit under 35 U.S.C. §119 from Chinese Patent Application No. 201310183990.2, filed on May 17, 2013, in China, the contents of which are hereby incorporated by reference. This application is a continuation-in-part of Chinese Application No. 201310183990.2.
The present invention relates generally to floor mats and, more particularly, to a mat with a gel layer that provides a massaging function.
Besides being used to wipe ones shoes, floor mats also provide cushioning to people who must stand for lengthy periods of time. For example, those who stand in the kitchen while preparing for and cleaning up from meals often experience sore feet. Some store clerks and assembly line workers also stand for extended periods and must endure fatigued feet and legs. Standing on a foam mat can reduce the soreness and fatigue caused by standing for lengthy periods. In addition, small bumps in the mat can produce a massaging sensation that lessens leg fatigue and reduces foot soreness. The foam is typically placed over the massaging bumps to produce a softer massaging sensation and so that the user's feet do not directly feel the hard bumps. The foam layer must be relatively thick, however, to dampen the hard feeling of the bumps. But a user is more likely to trip over a thick floor mat. The thickness of the cushioning material over the hard bumps can be reduced by adding a layer of resilient gel. Manufacturing such gel-based mats, however, can be difficult. The layers of foam and gel tend to shift with usage and when rolled for shipping such that the foam layer moves to one side of the mat interior, while the gel layer moves to the other side. A gel-based floor mat is sought that is efficient to manufacture and whose gel and foam layers do not shift with rolling and usage.
A massaging floor mat includes a layer of gel that penetrates into the cells of a layer of foam. The layer of gel and the portion of the gel that penetrates the foam are a contiguous amount of gel so that no separate drops of gel are dispersed in the foam. The layer of foam sits on a foundation layer of hard plastic. A plurality of protrusions are distributed over the upper surface of the foundation layer. The protrusions provide a massaging sensation to the user of the mat. The protrusions also hold the layer of foam in place obviating the need to glue the foam to the foundation layer. The gel is spread over the foam as a sheet of foam moves along a conveyor belt. The gel is then cured using hot air. The foundation layer is held in place in an indentation of a bottom cover of flexible plastic without using any glue. The hard plastic of the foundation layer is less flexible than the flexible plastic of the bottom cover. A top cover is placed over the layer of gel, which remains somewhat sticky. The top cover is then attached to the bottom cover at their peripheral edges using high-frequency welding.
The layer of foam is made of high density (HD) polyurethane foam, visco-elastic polyurethane memory foam or natural latex foam. In one embodiment, the layer of foam is memory foam with a density greater than five pounds per cubic foot and an indentation load deflection greater than twelve. The hard plastic of the foundation layer is made of polyvinyl chloride (PVC), hard rubber, polyurethane, polypropylene, polyethylene, polyvinyl acetate (PVA) or a thermoplastic elastomer (TPE). The flexible plastic of the bottom and top covers is a thermoplastic polyurethane (TPU) membrane laminated onto fabric or polyvinyl chloride (PVC). The plurality of protrusions are shaped as hemispheres or cylinders and are evenly disbursed in a matrix or are arranged in concentric circles on the upper surface of the foundation layer.
Other embodiments and advantages are described in the detailed description below. This summary does not purport to define the invention. The invention is defined by the claims.
The accompanying drawings, where like numerals indicate like components, illustrate embodiments of the invention.
Reference will now be made in detail to some embodiments of the invention, examples of which are illustrated in the accompanying drawings.
The lower surface 14 of foundation layer 11 is disposed over a bottom cover 15 of flexible plastic. For example, the flexible plastic is a thermoplastic polyurethane (TPU) membrane laminated onto fabric or a polyvinyl chloride (PVC) sheet. The hard plastic of foundation layer 11 is less flexible than the flexible plastic of bottom cover 15. For example, where both bottom cover 15 and foundation layer 11 are made of polyvinyl chloride (PVC), the PVC of bottom cover 15 is thinner, less rigid and more flexible than the PVC of foundation layer 11. Bottom cover 15 has and indentation 16 into which foundation layer 11 fits. Indentation 16 is surrounded by a peripheral lip 17.
A layer of foam 18 is disposed over foundation layer 11. Foam 18 is high density (HD) polyurethane foam, visco-elastic polyurethane memory foam or natural latex foam. In one embodiment, the layer of foam 18 is made with polyurethane memory foam having a density greater than five pounds per cubic foot and an indentation load deflection (ILD) greater than twelve. Foam with a higher density is not necessarily firmer. It is possible for memory foam to have an ILD greater than twelve and a density less than five pounds per cubic foot. The higher density memory foam is used in massaging floor mat 10 because higher density foam tends to wear better. A lower density foam used in a floor mat would eventually lose its resiliency and remain permanently compressed after years of being stood upon.
A layer of gel 19 is disposed over the layer of foam 18. The gel 19 is an elastomeric silicon-based gel, polyurethane-based gel or a polyether gel. In one embodiment, gel 19 is a blue polyether gel made from a polyether polyol and methylenediphenyl diisocyanate (MDI). The polyether polyol can be purchased from Huizhou YuanAn Industrial Co., Ltd in Guangdong, China, as product number YC-8902M47-A. The MDI can also be purchased from Huizhou YuanAn Industrial Co. Ltd as product number YC-8902M47-B, and is 4,4′-methylenediphenyl diisocyanate. A commercial name of the blue polyether gel is “Vgel”. The gel 19 has a higher heat capacity and thermal conductivity than does the foam 18. The higher thermal conductivity gives the gel a cooler feeling as heat is transferred away from warmer objects that are thermally coupled to the gel, such as the user's feet. Although the exploded view of
A top cover 20 is disposed over the layer of gel 19. Top cover 20 is made of a flexible plastic, such as a thermoplastic polyurethane (TPU) membrane laminated onto fabric or a polyvinyl chloride (PVC) sheet. Top cover 20 has the same outer dimensions as does bottom cover 15. Top cover 20 is attached to bottom cover 15 at their peripheral edges using high-frequency (ultrasonic) welding. Ultrasonic welding applies high-frequency ultrasonic acoustic vibrations to the two pieces of plastic that are being held together under pressure to create a solid-state weld. The high-frequency welding melts a portion of the peripheral lip 17 of bottom cover 15 into the perimeter of upper cover 20 and seals foundation layer 11 and the combined foam/gel layers 18-19 inside a flexible plastic covering of massage mat 10. By placing top cover 20 over the layer of gel 19 while the gel is still sticky and before the gel sets up, top cover 20 sticks to the layer of gel 19 without using any glue.
In step 31, a layer of liquid gel 19 is spread over a sheet of foam 18 such that a portion of the gel penetrates into cells of the foam. In one implementation, a layer of liquid blue polyether gel is spread over the sheet of foam as the sheet of foam is moved by a conveyor belt. The polyether gel is dispensed in a line perpendicular to the motion of the conveyor belt. The foam sheet with the thin layer of gel on the top then travels through a curing chamber in which hot air is blown over the gel so that the gel sets up and becomes firmer. However, the upper surface of the gel is still somewhat sticky. By spreading the layer of gel 19 over sheets of foam, the mat 10 can be more efficiently manufactured in a continuous assembly line process instead of by forming the gel for individual mats in a mold.
In step 32, the sheet of foam 18 with the upper layer of gel 19 is cut into sections that have the dimensions of foundation layer 11. In step 33, a cut section of foam 18 and gel 19 is placed over a foundation layer 11 that is sitting within indentation 16 of bottom cover 15. In step 34, top cover 20 is placed over the layer of gel 19, which is still somewhat sticky. The gel 19 inside the assembled mat is then allowed to cure for many hours. In an optional step 35, the curing process of the gel is sped up by again placing the assembled mat in a curing chamber through which hot air is blown.
Finally in step 36, top cover 20 is attached to bottom cover 15 at their peripheral edges using high-frequency welding. The high-frequency welding melts the upper surface of the peripheral lip 17 of bottom cover 15 to the perimeter of the lower surface upper cover 20. Foundation layer 11, foam 18 and gel 19 are thereby sealed inside the top and bottom covers. The efficient manufacturing method of
Although certain specific exemplary embodiments are described above in order to illustrate the invention, the invention is not limited to the specific embodiments. Accordingly, various modifications, adaptations, and combinations of various features of the described embodiments can be practiced without departing from the scope of the invention as set forth in the claims.
Number | Date | Country | Kind |
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201310183990.2 | May 2013 | CN | national |