WO2003045176A1

WO2003045176A1 - Fabric and protective structure for users of hand held power-driven chainsaws

Info

Publication number: WO2003045176A1
Application number: PCT/IT2002/000749
Authority: WO
Inventors: Roberto Fenzi
Original assignee: LENZI EGISTO SpA
Current assignee: LENZI EGISTO SpA
Priority date: 2001-11-28
Filing date: 2002-11-28
Publication date: 2003-06-05
Anticipated expiration: 2004-05-28
Also published as: EP1469753B1; ATE402623T1; ES2310616T3; DE60227997D1; ITPO20010008A1; AU2002358994A1; EP1469753A1; DK1469753T3; PT1469753E

Abstract

A fabric and a protective structure (20) for users of hand held power-driven chainsaws comprise a woven fabric (20), having a structure with floats designed to facilitate the rapid release of threads at the contact with the teeth of the saw and with 15-20 % by weight consisting of aramid yarns and 80-85 % of non-aramid yarns having a tenacity of at least 7 gr/dtex, and a supporting substrate (22) made of non-woven fabric, wadding, foam or a similar material, with a thickness of 3-5 mm, serving the purpose of providing sufficient space between the surface of the garment potentially exposed to the teeth of the saw and the skin of the user.

Description

FABRIC AND PROTECTIVE STRUCTURE FOR USERS OF HAND HELD

POWER-DRIVEN CHAINSAWS

DESCRIPTION

Technical Field This invention refers to a fabric and protective structure to be applied to articles of apparel such as pants, jackets, shoes and boots worn by users of hand held power-driven chainsaws, particularly woodcutters.

Background Art Protective fabrics that release threads in case of accidental contact of the teeth of a hand held power-driven chainsaw with the clothing of the user so as to stop the saw before it reaches the body are known. Some of these fabrics are described in US4279956, US5395683, US5415007 and EP202183. Another type of protective fabric is illustrated in US5876834: it includes a plurality of superposed layers of fabric made from yarns - particularly aramid yarns - having a tenacity of at least 10 grams per dtex woven in 1/3 satin weave. The layers of fabric are preferably alternated with layers of a felt, made from aramid staple fibers, weighing 100-140 gr/sq.mt. and having a thickness of 1-2.5 mm.

The known fabrics, in order to be effective in affording protection, have to be used in several layers stacked one on the other, with consequent addition of weight and limitation of the flexibility of the apparel in which they are used. Also, as regards the fabric described in US 876834, the exclusive use of aramid fibers results in a high cost of production.

Disclosure of Invention This invention arises from the insight - confirmed by tests carried out - that it is not necessary to provide several layers of fabric that release threads to block the teeth of the chainsaw, but that a single layer is generally sufficient, if the fabric has particular features and is used with a supporting layer of adequate thickness that serves to put sufficient distance between the surface exposed to the saw teeth and the skin of the user. Therefore, a first object of this invention is to provide a protective fabric that stops the chain of a power-driven saw in case of accidental contact with the teeth of the chain, even if only a single layer of fabric is used.

A second object of the invention is to provide a protective stmcture designed to be applied to the clothing worn by users of chainsaws that is light, flexible and economical to produce. These objects are achieved with a protective fabric and stmcture in conformity with the enclosed independent claims. Advantageous embodiments of the invention are defined in the dependent claims.

The technical characteristics and advantages of this invention will be clear from the detailed description that follows of a non limiting example of embodiment and of one of its variations.

Brief Description of Drawings In the drawings:

- fig. 1 illustrates a schematic plan view of a protective fabric in conformity with the invention; - fig. 2 and 3 illustrate cross-sectional views, taken along a warp thread and respectively a weft thread of the fabric shown in fig. 1, of a protective structure in conformity with a first mode of carrying out the invention;

- fig. 4 illustrates a schematic perspective view of a protective structure in conformity with a second mode of carrying out the invention; - fig. 5 illustrates a cross-sectional view taken along a warp thread of the fabric of the protective stmcture shown in fig. 4.

Best Mode for Carrying Out the Invention With reference to fig. 1, a protective fabric 10 according to the invention substantially consists of a woven fabric, with a wave of weft threads 12,13 and warp threads 14, having a stmcture with floats in the warp or weft designed to facilitate the rapid release of the threads upon contact with the teeth of a power-driven chainsaw, these floats preferably passing over at least 3 threads.

The fabric comprises 15-20 % by weight of aramid yams and 80-85 % of non-aramid yarns with a tenacity of at least 7 gr/dtex. More in particular, in this fabric, the warp yams 14 (or, alternatively, the weft yams) shall be made up exclusively of non-aramid yams.

It has been verified that, by using non-aramid fibers with a tenacity of even less than 10 gr/dtex, it is possible to produce a fabric that is effective even in a single layer, if used with a substrate of adequate thickness to create a protective stmcture, in case of accidental contact with the teeth of a chain saw.

Preferably, the protective fabric shall have the following construction:

- in the warp (or weft): from 17 to 22 yams per cm made of non-aramid fibers 14 with a tenacity between 7 and 8.5 gr/dtex e

- in the weft (or warp): from 5 to 7 yams per cm made of aramid fibers 12, with high tenacity, and of non-aramid fibers 13 with tenacity between 7 and 8.5 gr/dtex.

Non-aramid yams 13,14 can be nylon, polyester, polypropylene, polyethylene, LCD, PBO, having a linear density preferably between 560 and 1880 dtex, while aramid yams shall have preferably a linear density between 560 and 3000 dtex. Advantageously, in the weft (or warp) the aramid yams 12 shall alternate with non-aramid yams 13. A protective fabric, with a weave 1/3 satin, endowed with the following features:

- warp: 20 yams per cm of bright nylon 950 dtex with a tenacity of 7.7 gr/dtex;

- weft: 6 yams per cm of which, alternately, 3 yams per cm of bright nylon 950 dtex with a tenacity of 7.7 gr/dtex and 3 yams per cm of aramid fiber 1670 dtex, has a weight of 280 gr/sq.mt. in which only about 20% consists of aramid yams. Fig. 2 and 3 schematically illustrate, in cross-section along a warp yam 14 and respectively a weft yam 12, a protective stmcture 20 in which a single layer of fabric 10

- produced as specified above - is used with a supporting substrate 22 to form a protective stmcture suitable for application to the apparel worn by users of hand held power-driven chainsaws. This substrate 22, that has the substantial function of providing sufficient space between the surface of the garment potentially exposed to the teeth of the saw and the skin of the user, may consist of a synthetic non- woven fabric with a thickness of not less than 3 mm and weight of not more than 270 gr/sq.mt., made, for example, with fibers in polyester, polypropylene or polyethylene, worked with "Malivlies" technology and voluminized by means of DiLour or DiLoop machines. Advantageously the voluminized part 22a of the substrate 22 is in contact with the fabric 10.

In an alternative mode of production, the substrate may consist of a layer of 4-5 mm of thickness of a bicomponent fiber wadding of polyester in which a core is provided with an external heat-sensitive sheath. When the fibers are heated, the external heat-sensitive sheath melts so that the fibers bond together to form a supporting layer that maintains its resiliency even after multiple washings.

In order to stabilize the fabric 10, the stmcture 20 can be quilted. In this way it is possible to counteract any tendency of the yams of the fabric to alter their reciprocal positions due to manipulation, so as to become thinner in some zones with the risk of providing less protection.

Garments (pants and jackets) equipped with a protective stmcture, made using a fabric with a substrate as specified above, have passed the tests foreseen by standard EN 381. In a further mode of carrying out the invention, the substrate may consist of a foam material with a thickness of not less than 4 mm, in polyester, polyether, polyurethane or similar material, preferably open cell and with a density of at least 16 Kg/cu.mt. A protective structure in conformity with the invention, consisting of a single layer of non-woven material (wadding or foam) and a single layer of protective fabric is much more flexible than the multiple-layered stmctures used up to now, and about 60% lighter. Also, since only the external fabric and only 20% of it contains aramid fibers, the cost of production is also much lower than that of stmctures in which only those fibers are used. This means that apparel made with a fabric and protective stmcture according to the invention is more ergonomic and economical than the protective apparel now available on the market. Fig. 4 and 5 illustrate a mode of use of a fabric and a protective stmcture in conformity with the invention, in the case of garments (or parts of them) having a limited area potentially exposed to the action of the teeth of a chain saw, such as gloves and footwear. In this case it is advisable to use a portion 30 of fabric, measuring at least 30x30 cm, folded into at least two ply 32,34, so as to ensure a sufficient release of threads on contact with the teeth of the saw. The invention thus conceived can be modified in many ways and variants, all falling within the scope of the inventive concept. In particular, it may also be possible to use the fabric that releases threads described above to produce multiple-layered protective structures having several superposed layers of fabric and possibly one or more layers of a non-woven material, wadding, foam or the like, in turn also possibly alternating them with layers of the fabric. Also, all the details may be replaced by technically equivalent elements.

Claims

1. Woven protective fabric with a stmcture of warp and weft threads, of the type adapted to release threads and block the chain of a hand held power-driven chainsaw in case of accidental contact of the teeth of the chain, characterized in that the weave comprises warp floats or weft floats designed to facilitate rapid release of the threads at the contact with the teeth of a power-driven chainsaw and that 15-20 % by weight consists of yams made of aramid fibers and 80-85% of yams made of non-aramid fibers having a tenacity of at least 7 gr/dtex.

2. Protective fabric according to claim 1, characterized in that the non-aramid yams have a tenacity between 7 and 10 dtex and preferably between 7 and 8.5 dtex.

3. Protective fabric according to claim 1 or 2, characterized in that the warp yams consist exclusively of non-aramid yams and that, in the weft, aramid yams alternate with non-aramid yams.

4. Protective fabric according to claim 1 or 2, characterized in that the weft yams consist exclusively of non-aramid yams and that, in the warp, aramid yams alternate with non-aramid yams.

5. Fabric according to claim 3 or 4, characterized in that the weave is a 1/3 satin.

6. Fabric according to claim 5, characterized by the fact of comprising

- in the warp: from 17 to 22 and preferably 20 yams per cm of non-aramid fibers and - in the weft: from 5 to 7 and preferably 6 yarns per cm of aramid yams alternating with non-aramid yams.

7. Fabric according to one of the previous claims, characterized in that the non-aramid yarns are made of nylon, polyester, polypropylene, polyethylene, LCD or PBO, with a linear density between 560 and 1880 dtex, while the aramid yams have a linear density between 560 and 3000 dtex.

8. Fabric according to claim 6, characterized by the fact of comprising, in the warp, yarns of nylon 940 dtex with a tenacity of 7.7 gr/dtex and, in the weft, the same yarns alternating with aramid yams 1670 dtex.

9. Protective stmcture designed to be applied to garments for the users of hand held power-driven chainsaws, characterized by the fact of comprising a single layer of a fabric that releases threads, according to one of the claims from 1 to 8, superposed to a supporting layer having a thickness of 3-5 mm, with the function of providing sufficient space between the surface of the garment potentially exposed to the teeth of the saw and the skin of the user.

10. Protective stmcture according to claim 9, characterized in that said supporting layer consists of a layer of synthetic non-woven fabric having a thickness of not less than 3 mm and weight of not more than 270 gr/sq.mt., made, for example, from fibers of polyester, polypropylene or polyethylene, worked with Malivlies technology and voluminized by means of DiLour or DiLoop machines.

11. Protective stmcture according to claim 10, characterized in that the voluminized part of said layer of synthetic non-woven fabric is in contact with said layer of a fabric that releases threads.

12. Protective stmcture according to claim 9, characterized in that said supporting layer consists of a layer with a thickness of 4-5 mm of wadding in bicomponent fibers in which a core filament, for example in polyester, is coated with a heat-sensitive external sheath.

13. Protective stmcture according to claim 9, characterized in that said supporting layer consists of a layer with a thickness of 4-5 mm of foam in polyester, polyether, polyurethane and similar material, preferably open cell and with a density of not less than 16 Kg/cu.mt.

14. Protective stmcture according to one of the claims from da 9 a 13, characterized in that said layer of a fabric that releases threads and said supporting layer are each other stabilized by means of quilting.

15. Protective stmcture according to one of the claims from 9 to 14, characterized by in that the protective fabric has a length of at least 30 cm in the direction of the aramid yarns and is folded into at least two ply.

16. Protective stmcture, designed to be applied to garments for the users of hand held power-driven chainsaws, characterized by the fact of including a plurality of layers of a fabric that releases threads, according to one of the claims from 1 to 8, and possibly also one or more layers of non-woven, wadding, foam or similar material, in turn possibly alternating with the layers of fabric.