EP1203539A1

EP1203539A1 - An antistatic shoe sole

Info

Publication number: EP1203539A1
Application number: EP00309766A
Authority: EP
Inventors: Kent Chi-Huan Novel Worldwide Tr. Co. Ltd. Chen
Original assignee: Novel Worldwide Trading Co Ltd
Current assignee: Novel Worldwide Trading Co Ltd
Priority date: 2000-11-03
Filing date: 2000-11-03
Publication date: 2002-05-08

Abstract

A shoe sole (10) comprising at least one hole (130, 131) and a plug in the hole (130, 131), the plug comprising a conducting material for at least reducing static electricity build up in the shoe sole during use.

Description

This invention relates to a shoe sole and, more especially, this invention relates to an antistatic shoe sole.
There is already on the market an antistatic shoe sole which has an electrically conducting antistatic material inserted into the material that forms the shoe sole. The shoe sole is thus able to conduct electricity directly into the ground. This known shoe sole is patent registration No. 323461 in Taiwan and China. This known type of shoe sole has certain defects. More specifically, the shoe sole is made of a rubber or a plastics shoe material to which the antistatic material has been added. The antistatic material makes the entire shoe sole heavy, and thus shoes formed with the shoe soles are uncomfortable for a person to wear.
In addition, the antistatic material which is added to the basic shoe material tends to make the basic shoe material brittle and thus easily torn. This is especially so when the basic shoe material is a light weight shoe material such for example as ethylene vinyl acetate or rubber material. The abrasive ability of the basic shoe material is also weakened. The shoe sole is then not able to perform to the standard required by CE EN345-1 S3. Thus shoe sole materials such for example as the ethylene vinyl acetate or rubber material cannot satisfactorily be used when constructing an antistatic shoe sole, but these materials are desirable for use with footwear that is to be of a light weight, for example sports shoes known as trainers.
It is an aim of the present invention to reduce the above mentioned problem.
Accordingly in one non-limiting embodiment of the present invention there is provided a shoe sole comprising at least one hole and a plug in the hole, the plug comprising a conducting material for at least reducing static electricity build up in the shoe sole during use.
The shoe sole of the present invention is advantageous in that the static electricity is able to be reduced or eliminated by the use of the plug. Because the plug does not extend over the entire surface of the shoe sole, the weight of the shoe sole does not become too heavy as occurs with the above mentioned known antistatic shoe sole. Also, the plug does not make the remainder of the material of the shoe sole of the present invention brittle, easily torn and weak by lacking in abrasive ability. Thus the shoe sole of the present invention also does not suffer from this type of problem which occurs with the above mentioned known shoe sole. The shoe sole of the present invention can be used to form footwear which can be worn for a long time in a comfortable manner and without premature wear.
The shoe sole may be one in which the sole has a heel part and a front part, and in which there are at least one of the holes and at least one of the plugs in the heel part and/or at least one of the holes and at least one of the plugs in the front part.
In one embodiment of the invention, the shoe sole is one in which there are one of the holes and one of the plugs in the heel part, and in which there are two of the holes in the front part, and one plug having two plug portions for fitting in the two holes of the front part.
The or each hole in the sole may be of any suitable and appropriate size and shape. Preferably, the sole is one in which the or each hole is T-shaped in section so that it has top and bottom portions with the top portion being larger than the bottom portion.
The or each plug may be secured in the sole by any suitable and appropriate means. Preferably, the or each plug is secured in position with an adhesive. Any suitable and appropriate adhesive may be employed.
The sole may be one in which the or each plug is made of a first material which is suitable for forming part of the shoe sole, and a second material which is a conducting material for conducting the static electricity away from the sole.
The first material is preferably a rubber material or a plastics material. The rubber material or the plastics material may be solid material or foam material. A presently preferred plastics material is polyurethane material. Any suitable and appropriate rubber material or plastics material may be employed.
The second material may be in the form of an electrically conducting powder, or filaments or strands. The second material may be a metal or a non-metal. The second material may be of the same type and formation as that used in the known antistatic sole. Preferably, the second material is that known as electrostatic discharge material, also known as ESD inorganism.
The sole is preferably made of a rubber material or a plastics material. The rubber material may be a foam rubber material and the plastics material may be a foam plastics material. A presently preferred plastics material is ethylene vinyl acetate material.
The or each plug may extend through the shoe sole such that the or each plug finishes level with the bottom of the shoe sole. Alternatively, the or each plug may extend through the shoe sole such that the or each plug finishes proud of the bottom of the sole. With such a construction, the or each plug will usually finish only slightly proud of the bottom of the shoe sole.
The shoe sole may be one which includes a thin layer of shoe material which acts as a covering for the or each plug on the inside face of the shoe sole.
The present invention also extends to a shoe when including a shoe sole of the invention. The shoe may be any desired type of shoe including shoes for sport purposes such as trainers, and shoes for normal day use.
Embodiments of the invention will now be described solely by way of example and with reference to the accompanying drawings in which:
Figure 1 is an exploded perspective view of a first shoe sole;
Figure 2 shows the shoe sole of Figure 1 but with two plugs in position;
Figure 3 is a cross section through a second shoe sole, and taken on the line 3 - 3 shown in Figure 4; and
Figure 4 is a top plan view of the shoe sole shown in Figure 3.
Referring to Figures 1 and 2, there is shown a shoe sole 10 having a heel part 12 and a front part 11. The shoe sole 10 is made of a light weight flexible foam material such for example as ethylene vinyl acetate (EVA) or rubber. The heel part 12 has a hole 131. The front part 11 has two holes 130. The hole 131 is closed by a plug 201. The two holes 130 are joined at upper portions as shown. The two holes 130 are closed by a single plug 200 which has two depending plug portions as shown for fitting in the two holes 130.
The holes 130, 131 may be regarded as being T-shaped in section so that each hole 130, 131 has top and bottom portions with the top portion being larger than the bottom portion.
The plugs 200, 201 are secured in position with an adhesive. The adhesive can be any of the adhesives currently used for securing parts together in shoe soles and shoe uppers. The adhesive is preferably applied to both the plugs and the sides of the holes in which they fit. This tightly secures the plugs in position, in a water-tight manner. If desired, the adhesive can be applied to just the plugs or just the sides of the holes.
The plugs 200, 201 are made of a first material which is suitable for forming part of the shoe sole, and a second material which is a conducting material for conducting the static electricity away from the sole. The first material is a rubber material or a plastics materials, with a preferred plastics material being polyurethane material. The second material is an electrically conductive material known as ESD inorganism (electrostatic discharge inorganism).
The sole may be made of any suitable and appropriate material. The sole may be formed from a material that makes the shoes light weight, anti-slip and oil-resistant. Preferably the sole is made of a rubber material or a plastics material. The rubber material may be a foam rubber material and the plastics material may be a foam plastics material. Solid materials may however be employed if desired. Preferably, the plastics material is ethyl vinyl acetate foam material.
The plugs 200, 201 are such that they extend through the shoe sole 10 and finish level with the bottom of the shoe sole 10.
Figures 3 and 4 show a shoe sole 10 which is substantially identical to the shoe sole 10 shown in Figures 1 and 2 except that it can be seen from Figure 3 that the plugs 200, 201 extend through the shoe sole such that each plug 200, 201 finishes slightly proud of the bottom of the shoe sole, for example by 3mm. Also, the shoe sole 10 shown in Figures 3 and 4 has a front part 11 and a heel part 12 of a different thickness. With the plugs 200, 201 extending slightly proud of the bottom of the shoe sole 10 as shown in Figure 3, good contact with the ground for static electricity conduction is achieved.
The shoe soles 10 shown in the drawings have a thin layer of shoe material (not shown) on the upper surface of the shoe sole 10. This thin layer of shoe material hides the plugs 200, 201. This thin layer of shoe material also helps to retain the plugs 200, 201 firmly in position. The thin layer of shoe material may be stuck in position.
The drawings thus show antistatic shoe soles 10 which can be made of ethyl vinyl acetate or rubber foam material, which have an antistatic function, but which are still light and which can therefore be worn comfortably. The antistatic function is due to the use of the plugs 200, 201 which contain electrically conducting material. The plugs are provided at appropriate places on the shoe soles. The plugs 200, 201 do not cause the remainder of the material of the shoe soles 10 to become brittle and easily torn, and also to become weak by losing their abrasive ability. The shoe soles of the present invention are thus able to easily be worn, to give good wear use, and to comply with CE EN345-1 S3 standard.
It is to be appreciated that the embodiments of the invention described above with reference to the accompanying drawings have been given by way of example only and that modifications may be effected. Thus, for example, the or each hole in the shoe sole can be made as a prefabricated hole during formation of the shoe sole. Alternatively, the or each hole can be made after fabrication of the shoe sole. The or each hole may be regarded as an aperture or a cavity. The antistatic plugs can be of any suitable shape and size. Thus, the or each plugs may be in the shape of a wedge or a bar rather than being generally tubular as shown in the drawings. A wide variety of electrically conducting materials may be incorporated in the plugs in order to give the plugs and therefore the shoe soles the required antistatic function. Where more than one plug is employed in the sole, then the plugs may be of the same or different constructions. The holes in the shoe sole can be counter-bored as shown in the drawings or they can be of other shapes.

Claims

A shoe sole comprising at least one hole and a plug in the hole, the plug comprising a conducting material for at least reducing static electricity build up in the shoe sole during use.
A shoe sole according to claim 1 in which the sole has a heel part and a front part, and in which there are at least one of the holes and at least one of the plugs in the heel part and/or at least one of the holes and at least one of the plugs in the front part.
A shoe sole according to claim 2 in which there are one of the holes and one of the plugs in the heel part, and in which there are two of the holes in the front part and one plug having two plug portions for fitting in the two holes in the front part.
A shoe sole according to any one of the preceding claims in which the or each hole is T-shaped in section so that it has top and bottom portions with the top portion being larger than the bottom portion.
A shoe sole according to any one of the preceding claims in which the or each plug is secured in position with an adhesive.
A shoe sole according to any one of the preceding claims in which the or each plug is made of a first material which is suitable for forming part of the shoe sole, and a second material which is a conducting material for conducting the static electricity away from the shoe sole.
A shoe sole according to any one of the preceding claims in which the first material is a rubber material or a plastics material.
A shoe sole according to claim 7 in which the plastics material is a polyurethane material.
A shoe sole according to any one of claims 6 - 8 in which the second material is an electrostatic discharge material.
A shoe sole according to any one of the preceding claims in which the sole is made of a rubber material or a plastics material.
A shoe sole according to claim 10 in which the rubber material is a foam rubber material, and in which the plastics material is a foam plastics material.
A shoe sole according to claim 10 or claim 11 in which the plastics material is ethyl vinyl acetate.
A shoe sole according to any one of the preceding claims in which the or each plug extends through the shoe sole such that the or each plug finishes level with the bottom of the shoe sole.
A shoe sole according to any one of claims 1 - 12 in which the or each plug extends through the shoe sole such that the or each plug finishes proud of the bottom of the shoe sole.
A shoe sole according to any one of the preceding claims in which the shoe sole includes a thin layer of shoe material which acts as a covering for the or each plug on the inside face of the shoe sole.
A shoe when including a shoe sole according to any one of the preceding claims.