The present invention is a Continuation in part of a prior application U.S. Ser. No. 10/652,651 filed on Sep. 2, 2003, now abandoned.
The present invention refers to a preceding invention of the same author U.S. Pat. No. 10/652,651.
A search in the prior art revealed some systems that caught our attention:
HANES U.S. Pat. No. 6,866,913 issued on Mar. 15, 2005 recognizes including a piece of hook material, an adhesive strip attached to the hook material for attaching to the lower end of a furniture leg, and a piece of felt pad having a plurality of loop members for removably engaging the hook material.
SHEPARD U.S. Pat. No. 6,329,016 issued on Dec. 11, 2001 discloses needle-punching operations applying a foamed acrylic binder in the fabrication of loop products.
MANOR U.S. Pat. No. 5,807,161 issued on Sep. 15, 1998 describes a sanding application where mushroom type is being used and considered as performant as a J type hook material.
Our findings have been to the effect that for sliding a felt pad over a floor especially if there is an appreciable weight thereupon, the structure of the hook members of the felt pad must provide generally equal resistance in shear in all directions, which is the case when the hooks are of a mushroom type, typically having a hard core latex. The mushroom type further allows the use of shallow hooks evenly distributed and not exceeding about 1.45 mm in height.
According to an aspect of the present invention, there is provided a protector pad for use with a piece of furniture with legs, the pad comprising a generally flat body with two opposite pad faces:
Typically, a central layer of said sole, located between said lower and upper layers, comprises a reinforced material, preferably comprising a felt impregnated by a hardened material coming from a group comprising a latex base.
In the following description and in the accompanying drawings, the numeral numbers refer to identical parts in the various Figures.
The sole 34 is made of three sections: a superior section 42 made of a material comprising fibers 44 forming arches which will be restrained by the mushroom-like members in a way that the sole may be fixed upon the base. The sole also comprises a bottom section 46 made of a soft material that may slide without damaging floor surfaces. The sole also comprises a middle section 48 which is made of a firm material. This way the complete sole is much more resistant to shear stress constraints. Typically, in the bottom and top sections felt may be used as material. It is also possible to build the sole material by joining two sheets of felt using a heat process at the surfaces which are in contact. In this way, the center material melts and then hardens, constituting the firmer center section material. In production both sheets of felt are unrolled and gradually approached to each other. At the moment of junction, a flame causes the fibers at the surface of the contact surfaces to melt and join, and then harden. This type of felt has a better shear resistance than the original material, and gives a stronger resistance to the entire assembly. This is very important for a long lasting protector pad.
We found the problem with this construction is that the adhesive tape is only in contact with a fraction of the upper surface because this surface is irregular. Since it is embossed, only the elevated fraction of the surface keeps contact with the tape. Furthermore, since the upper surface of the protector pad is porous, water, soap and humidity may infiltrate and attack the adhesive tape when the pad is exposed to such elements in events such as mopping of the floors. The adhesive tape is very weak against water and has a tendency to lose its adhesion either to the pad or to the underneath of the furniture legs as soon as it is moistened. This may lead to the loss of the protective pad and to floor damage when the loss goes unnoticed. This is why a strong, durable and water-resistant adhesion is not only important to protect floors, but critical.
The felt may break down in layers or by pieces. In order to reinforce the felt sole in the prior art model, stronger fibers 54 are added to the typical felt material 52. These stronger reinforcing fibers are firmer than felt and therefore may damage the floor surface noticeably if it is slided repeatedly. It will not damage the surface as the furniture legs might however produce a long term scratching effect. This is why we found it is imperative to provide a lower surface made entirely of soft material.
Weight density: 370 g/m2
Unit density: 110 heads/cm2
Peel strength: 5 N/cm2
Shear strength: 60 N/cm2
Breaking strength: 350 N/cm
A protector pad for use with a piece of furniture with legs, the pad comprising a generally flat body 30 with two opposite pad faces:
The member hooks 36 defines mushroom type hooks comprising a unit density of a number of about 110 heads/cm2 of a height not exceeding about 1.45 mm. The mushroom shapes offer a form of hook which is equally strong all around, on 360°, in shear resistance. They tend to grab more than one fiber at a time. Hence, they are resistant to shear effort applied in any direction and stay easy to change when an effort is applied in tension (peel).
The shear resistance has a strength of about 60 N/cm2.
The weight density of the member hooks 36 is at least about 350 g/m2 and having a breaking strength of about 350 N/cm.
The second means of assembly 42 comprise fibers forming arches 44, the upper layer 42 of the sole 34 comprises a felt the fibers thereof forming the arches, the felt comprises materials from a group comprising polyester and natural fibers, the superior layer 42 and inferior 46 layers are made of felt material, the felt material consists either of polyester or natural fibers.
The said reinforced material is hardened felt comprising injected latex.
The grabbing member hooks 36 providing a high shear resistance are of a mushroom shape of a height shorter than a corresponding height of a J-shape hook 58, such that the hooks of the present invention are stiffer, in the shear direction, than the conventional J-shape hooks.
In the present invention there are no melt fibers added thereby maintaining softness of felt pad (felt pads for such application have been sold in the U.S. since 1991). Moreover, the mushroom hooks provide a much stronger gripping power (360°) than the Hanes' protection system: comparing to the Hanes′ system equipped with loop hooks, my system outfitted with mushroom hooks grip on automatically over a multitude of felt fibers and consequently, render my invention more efficient. I have shown a shear test figure (
This invention is particularly efficient because of a need of keeping softness of felt in contact with floor and to provide extra shear strength.
It is to be clearly understood that the instant description with reference to the annexed drawing is made in an indicative manner and that the preferred embodiments described herein are meant in no way to limit further embodiments realizable within the scope of the invention. The matter which is claimed as being inventive and new is limited only by the following claims.
Number | Date | Country | |
---|---|---|---|
Parent | 10652651 | Sep 2003 | US |
Child | 12150648 | US |