EP2146593A1

EP2146593A1 - Accessory for anti-electric-shock garment

Info

Publication number: EP2146593A1
Application number: EP07736715A
Authority: EP
Inventors: Rinaldo Carraro
Original assignee: Carraro SRL
Current assignee: Carraro SRL
Priority date: 2007-03-22
Filing date: 2007-03-22
Publication date: 2010-01-27
Also published as: WO2008114295A1

Abstract

The present invention relates to a glove or a boot, for operations on live high-voltage wires, comprising a first layer made of polymer fibre covered with conductive material and a second layer comprising a second material having high mechanical properties, joined together in a stable manner, wherein an end portion exhibits the first material both on the outside and on the inside.

Description

Title: 'ACCESSORY FOR ANTI-ELECTRIC-SHOCK GARMENT'

The present invention relates to an anti-electric-shock garment, such as for example a glove or a boot, according to the preamble of claim 1.

Such garments are intended to protect the technicians who perform aerial repairs on live high- voltage wires.

In the prior art some protective garments are known that aim to give protection from static electricity discharges, such as for example those of stun guns, or from more or less intense electromagnetic fields, such as the protective garments for the technicians who repair antennas.

Obviously these garments are not technically suitable for protection for aerial operations on high- voltage wires inasmuch as the former have to resist relatively limited voltages (max. 50 kV, versus the 800 kV of the high voltage) in DC and for short periods, while the latter have to resist relatively high-frequency electromagnetic fields (of the order of MHz or GHz, versus the 50/60 Hz of the high voltage) that generate decidedly lower-intensity currents; moreover, neither of the two types of garment needs to withstand high mechanical stresses.

For these reasons the technicians who perform maintenance operations on live high-voltage wires generally wear protective overalls produced from steel wire braided with cotton thread.

However, these overalls are not capable of providing optimal protection inasmuch as the maximum electrical resistance ^• between any two points of the garment is relatively high; moreover, being made of steel wire, they are more rigid and uncomfortable to use, impeding and hampering movements, with a consequent decrease in safety for the operators. Furthermore, to the greater discomfort of the operators, the gloves associated with these overalls do not have a satisfactory mechanical resistance. The technicians are therefore obliged to wear protective gloves and boots over the overalls. The gloves, in particular, which are made of thick hide, cancel the sensitivity of the hands almost completely, further decreasing the safety margins in some operations.

For this reason, a European Standard, IEC 60895:2002, was approved recently that defines some parameters that have to be measured to characterise garments that are suitable for these purposes, among them:

• resistance to abrasion and to wear;

• flame-retardant properties;

• low electrical resistance;

• capacity to conduct capacitive currents;

• protection and shielding capacity;

• resistance to cleaning cycles;

• protection against sparks.

Besides these parameters, the Standard defines other parameters specific to garments that protect only some parts of the body: for gloves, boots, socks, and footwear, the measuring method of the maximum resistance measure is defined; for garments that shield the head and the face, the efficiency of protection of the face is also defined.

The necessity for safety garments that are ever more effective and simple to use in this field is continually underlined by the too frequent accidents recorded almost daily all over the world.

The present invention is therefore aimed at satisfying specifically the needs of operators who carry out maintenance work on high-voltage electrical lines.

It would therefore be desirable to produce a garment such as for example a glove or a boot that can combine high mechanical strength with excellent comfort during use, in such a way as to make the use of further gloves and/or boots no longer necessary. In view of the prior art described, the object of the present invention is to obtain such a garment.

According to the present invention, this object is achieved by means of a garment in accordance with claim 1.

The features and the advantages of the present invention will become evident from the following detailed description of a practical embodiment given as a non-limiting example with reference to the attached drawings in which:

— figure 1 shows a boot according to a first preferred embodiment of the present invention;

— figure 2 shows a glove according to the first preferred embodiment of the present invention;

— figure 3 shows a glove according to a second preferred embodiment of the present invention;

— figure 4 shows a glove according to a third preferred embodiment of the present invention;

— figure 5 shows a glove according to a fourth preferred embodiment of the present invention.

The present invention relates in particular to a glove 1 or to a boot 2 that are joined by having an open end portion 3 for inserting the hand or the foot of the user. In the course of the description, the term garment will be used to describe both, but this is not intended to limit the invention to a glove 1 and/or a boot 2 only.

According to the invention, the protective garment for operations on live high-voltage wires is preferably a glove 1 or a boot 2 and comprises a first layer 4 comprising a first conductive material. Advantageously, the extent of the said first layer 4 is substantially equal to that of the said garment, that is, the garment is made of a substantially complete first electrically conductive layer 4.

The garment can also advantageously comprise a second layer 5, joined to the first layer 4 in a stable manner. The second layer 5 can comprise a second material having flame-retardant properties and/or an elevated resistance to wear; advantageously, the first layer 4 is arranged on the inside of the second layer 5.

In this way it is possible to overcome the disadvantages of the garments existing in the prior art inasmuch as a garment is obtained that has excellent mechanical properties and excellent electrical properties.

As a matter of fact, it was noticed that when the gloves or the boots were produced according to the teachings of the international patent application with the title 'ANTI-ELECTRIC- SHOCK GARMENT', filed by the present applicant on 22 March 2007, they wore out in a particularly rapid manner.

Surprisingly, arranging the first conductive layer 4 on the inside of the garment increases its durability even when a further protection is used over it, as for example a glove and/or a boot made of hide.

One explanation that has been considered plausible for this phenomenon is that effects of electrocorrosion caused by chemical products (among them chromium and sulphur) used in the tanning of the hides used for the gloves or for the protective boots employed in the field up to now can be avoided in this manner.

According to a first preferred embodiment of the invention, the material of the first layer 4 is a first textile product, preferably obtained from a polymer thread or filament covered with conductive metal, such as for example silver, while the material of the second layer 5 is a second textile product obtained from a fibre endowed with good fire resistance, such as for example a polyaramide or meta-polyaramide fibre. 'Good fire resistance' is understood to mean that the fibre has flameproof and/or flame- retardant properties that can be taken advantage of in the textile field of clothing. In this sense, this term can be understood to exclude both mineral fibres, which cannot be woven except with great difficulty, and metallic fibres which, although resistant to extremely high temperatures, are not suitable for garments for high temperatures inasmuch as they are good conductors of heat.

Using silver as a conductor, a garment also endowed with antibacterial and bacteriostatic properties is advantageously obtained.

The two layers 4, 5 can be connected together in a stable manner by means of quilting or, more advantageously, by means of connection (chemical or mechanical) over the entire extent of their contact surfaces.

The connection can be achieved both chemically, that is by placing a resin between the two yarns, for example a flameproof and preferably polyurethane resin, that acts as an adhesive without compromising the elastic properties of the knits, and mechanically, that is by weaving at least one conductive thread for the first layer 4 and at least one thread for the second layer 5 at the same time, but separated, on the same weaving machine.

In accordance with a second preferred embodiment of the invention (not shown in the figures), the material of the first layer 4 is a first textile product obtained from a fibre having good fire resistance. This first textile product can be for example the yarn obtained according to the teachings of the international patent application with the title 'CONDUCTIVE TEXTILE YARN', filed on 22 March 2007 in the name of the holder of the present application.

In this case, it can be a twisted yarn obtained by twisting a polyamide filament covered with silver with an aramide thread or obtained by twisting together polyamide fibres covered with silver and polyaramide fibres or flame-retardant viscose fibres. The material of the second layer 5 can be, in this case, a non-textile product having even better mechanical characteristics than those of the first material, such as for example made of hide or synthetic hide.

Advantageously, in an end extremity 3 of the garment, the first layer 4 is on the outside of the garment itself; as can be seen in the figures, the end extremity 3, that is the end from which the hand is inserted (into a glove) or the foot is inserted (into a boot), is preferably open.

According to the first embodiment, the first conductive layer 4 is arranged on the outside preferably thanks to a cuff 6 of this end portion 3, in such a way that the first layer 4 is present both on the outside and on the inside of the garment.

The cuff 6 is preferred to a stitch inasmuch as it does not introduce a further interface between two distinct elements of the first electrically conductive layer 4.

In figures 2 and 3 it is more clearly visible that the first layer 4 turned to the outside extends for a longitudinal distance L sufficiently long to allow the application of conductive means 7 that place the external portion 8 of the first layer 4 in electrical contact with the internal portion 9 of the same, in addition to the electrical connection produced by the continuity of the textile product.

The longitudinal distance L is advantageously at least one cm, in such a way as to allow also the application of one or more press studs 10 over it. These press studs 10, produced from metal, can constitute the above-mentioned conductive means 7, and at the same time allow the joining of the garment described here to other garments complementary to it, such as for example overalls.

According to the second preferred embodiment of the present invention, the first layer 4 is exposed both on the outside and on the inside of the garment in correspondence with one of its extremities 3 inasmuch as the second layer 5, which in this embodiment can be obtained from a layer of hide, leather, or synthetic hide, is not present in correspondence with this extremity 3. The portion in which the external protective layer is not present extends for a distance L, exactly as in the previous embodiment, and can be similarly provided with press studs.

According to a further preferred embodiment of the present invention, illustrated in figure 4, at least one portion comprises a third layer of protection 11, arranged on the outside of the second layer 5.

This third layer 11 is produced from a material having mechanical strength superior to that of the second layer 5.

When the garment is a glove 1, the third layer 11 will be arranged in correspondence with at least one part of the lower side of the glove 1, advantageously over the entire lower side of the glove 1, preferably only on the lower side of the glove 1. When the garment is a boot 2, the third layer 11 can be arranged in correspondence with the sole of the foot, preferably only in correspondence with it, to produce a sole.

The third layer 11 is preferably produced from hide, leather, or synthetic hide.

Obviously the person skilled in the art, for the purpose of satisfying contingent and specific needs, will be able to introduce numerous modifications and variants to the configurations described above, but all contained within the scope of protection of the invention as defined by the following claims.

Claims

1. Protective garment, for example glove (1) or boot (2), for operations on live high- voltage wires, characterised in that

~ the said garment comprises a first layer (4) comprising a first conductive material.

2. Garment according to the preceding claim, comprising a second layer (5) comprising a second material having good fire resistance;

— said first layer (4) being joined in a stable manner to said second layer; ~ said first layer (4) being arranged on the inside of said second layer (5).

3. Garment according to the preceding claim, wherein said first material is a filament covered with conductive material.

4. Garment according to either claim 1 or claim 2, wherein said first material is a thread comprising fibres of conductive material twisted with polymer fibres endowed with good fire resistance.

5. Garment according to any one of the preceding claims, wherein the said first and second layer (4, 5) are joined together in a stable manner, preferably by means of a polyurethane resin placed between them.

6. Garment according to any one of the preceding claims, wherein an end portion (3) of the said garment exhibits the said first material both on the outside and on the inside of the said garment.

7. Garment according to the preceding claim, wherein said end portion (3) comprises a cuff (6).

8. Garment according to either claim 6 or claim 7, comprising at least two press studs (10) for joining to other garments complementary to it, arranged in the said end portion (3).

9. Garment according to any one of the preceding claims, wherein said garment is a glove (1) and comprises a layer (5, 11) of hide, leather, or synthetic hide, arranged in correspondence with the lower side of said glove (1).

10. Garment according to the preceding claim, wherein said layer (5, 11) is arranged on all and only the lower side of said glove (1).